CCNP Routing and Switching ROUTE 300-101 Official Cert Guide (2015)
Part II. IGP Routing Protocols
Chapter 6. EIGRP for IPv6 and Named EIGRP
This chapter covers the following subjects:
EIGRP for IPv6: This section compares and contrasts EIGRP for IPv4 and for IPv6, and shows how to configure EIGRP for IPv6. Verification commands are also covered in this section.
Named EIGRP: This section examines an alternate approach to configuring EIGRP. While traditional EIGRP configuration necessitates that some commands be entered under interface configuration mode and other commands be entered under router configuration mode, Named EIGRP allows those commands to be entered collectively, under a single EIGRP virtual instance.
EIGRP’s original architecture allowed it to support the routing of multiple protocols, including IPv4, IPX, and AppleTalk. As a result, it was not difficult for Cisco to allow IPv6 support with Enhanced Interior Gateway Routing Protocol (EIGRP). One of the primary configuration differences between EIGRP for IPv4 and EIGRP for IPv6 is how an interface is told to participate in an EIGRP autonomous system (AS). As you’ll see in this chapter, you enter interface configuration mode and directly tell the interface to route IPv6 traffic as part of a specific EIGRP AS, as opposed to using a network command in router configuration mode for EIGRP.
Another fairly recent enhancement to EIGRP is a new hierarchical approach to configuration, specifically Named EIGRP configuration. While the configuration of Named EIGRP might seem more complex at first, it allows you to enter all your EIGRP configuration commands under a single configuration section, rather than going back and forth between interface configuration mode and router configuration mode, which introduces the possibility of mistyping the EIGRP AS every time you go back into router configuration mode. Also, for many complex EIGRP configurations, a Named EIGRP configuration requires fewer commands than classic EIGRP configuration.
“Do I Know This Already?” Quiz
The “Do I Know This Already?” quiz allows you to assess whether you should read the entire chapter. If you miss no more than one of these six self-assessment questions, you might want to move ahead to the “Exam Preparation Tasks” section. Table 6-1 lists the major headings in this chapter and the “Do I Know This Already?” quiz questions covering the material in those headings, so that you can assess your knowledge of these specific areas. The answers to the “Do I Know This Already?” quiz appear in Appendix A.
Table 6-1 “Do I Know This Already?” Foundation Topics Section-to-Question Mapping
1. You are attempting to configure EIGRP for IPv6 on a router. However, Cisco IOS presents you with a message indicating that routing is not enabled for IPv6. What command would you issue to enable IPv6 routing?
a. Router(config)# ipv6 unicast-routing
b. Router(config-rtr)# ipv6 unicast-routing
c. Router(config-rtr)# ipv6 cef
d. Router(config)# ipv6 eigrp
2. Router R1 connects to Router R2 over an Ethernet LAN with both routers using their Fa0/0 interfaces. R1 learns a route from R2 using EIGRP for IPv6. That route lists Fa0/0 as the outgoing interface with R2 as the next hop. The configuration excerpt shows all relevant configuration on R2’s Fa0/0 interface. Which of the following is true about R1’s route?
interface f0/0
mac-address 1111.1111.1111
ipv6 address 2000::/64 eui-64
ipv6 address 2001::1/64
a. The next hop is 2000::1311:11FF:FE11:1111
b. The next hop is FE80::1311:11FF:FE11:1111
c. The next hop is FE80::5111:11FF:FE11:1111
d. The next hop is 2001::1
3. Under what configuration mode for Named EIGRP would you configure a passive interface?
a. Address-Family configuration mode
b. Address-Family-Interface configuration mode
c. Address-Family-Global configuration mode
d. Address-Family-Topology configuration mode
4. Under what configuration mode for Named EIGRP would you configure variance?
a. Address-Family configuration mode
b. Address-Family-interface configuration mode
c. Address-Family-Global configuration mode
d. Address-Family-Topology configuration mode
5. When configuring Named EIGRP, you want to specify the Hello interval for all interfaces. You could go into address-family-interface configuration mode for each interface and enter the hello-interval command. However, what command could you give from address-family configuration mode to go into a configuration mode that allowed you to configure the Hello Interval for all interfaces with a single hello-interval command?
a. address-family global
b. af-interface default
c. af-interface-all
d. address-family *
6. You configured a router with a Named EIGRP configuration. What command would you use to view the EIGRP for IPv4 topology table?
a. show address-family ipv4 topology
b. show ip eigrp topology
c. show address-family-topology
d. show ip address-family
Foundation Topics
IPv6 is no longer a curiosity that we know we will need to migrate to someday. IPv6 is happening all around us right now. So, we have to be able to support it on our networks. What IGP routing protocol options do we have for IPv6? Well, the common ones we might think of are RIP next generation (RIPng), EIGRP, and Open Shortest Path First version 3 (OSPFv3). The choice of which routing protocol to use will probably be based on what we are currently using to route IPv4 traffic.
However, if you are currently running EIGRP for your IPv4 networks, you might want to stay with EIGRP as your interior gateway protocol (IGP) of choice to support IPv6 traffic. That is the focus of the first section in this chapter.
The second major section of this chapter introduces you to a new paradigm for EIGRP configuration, called named mode configuration, which we will also refer to as Named EIGRP. This hierarchical approach to configuration can help reduce configuration errors, while being more efficient for complex EIGRP configurations.
EIGRP for IPv6
Cisco originally created EIGRP to advertise routes for IPv4, IPX, and AppleTalk. This original EIGRP architecture easily allowed for yet another Layer 3 protocol, IPv6, to be added. As a result, Cisco did not have to change EIGRP significantly to support IPv6, so many similarities exist between the IPv4 and IPv6 versions of EIGRP.
Note
Many documents, including this chapter, refer to the IPv6 version of EIGRP as EIGRP for IPv6. However, some documents at www.cisco.com also refer to this protocol as EIGRPv6, not because it is the sixth version of the protocol, but because it implies a relationship with IPv6.
This section begins with a discussion of the similarities and differences between the IPv4 and IPv6 versions of EIGRP. The remaining coverage of EIGRP in this section focuses on the changes to EIGRP configuration and verification in support of IPv6.
EIGRP for IPv4 and IPv6: Theory and Comparisons
For the most part, EIGRP for IPv4 and for IPv6 have many similarities. The following list outlines some of the key differences:
EIGRP for IPv6 advertises IPv6 prefixes/lengths, rather than IPv4 subnet/mask information.
EIGRP for IPv6 uses the neighbor’s link-local address as the next-hop IP address; EIGRP for IPv4 has no equivalent concept.
EIGRP for IPv6 encapsulates its messages in IPv6 packets, rather than IPv4 packets.
EIGRP for IPv4 defaults to use automatic route summarization at the boundaries of classful IPv4 networks. IPv6 has no concept of classful networks, so EIGRP for IPv6 cannot perform any automatic summarization.
EIGRP for IPv6 does not require neighbors to be in the same IPv6 subnet as a requirement to become neighbors.
Other than these differences, most of the details of EIGRP for IPv6 work like EIGRP for IPv4. For reference, Table 6-2 compares the features of each.
Table 6-2 Comparing EIGRP for IPv4 and IPv6
Configuring EIGRP for IPv6
EIGRP for IPv6 follows the same basic configuration style as for RIPng. The specific EIGRP for IPv6 configuration steps are as follows:
Step 1. Enable IPv6 routing with the ipv6 unicast-routing global command.
Step 2. Enable EIGRP using the ipv6 router eigrp {1 – 65535} global configuration command.
Step 3. Enable IPv6 on the interface, typically with one of these two methods:
Configure an IPv6 unicast address on each interface, using the ipv6 address address/prefix-length [eui-64] interface command.
Configure the ipv6 enable command, which enables IPv6 and causes the router to derive its link-local address.
Step 4. Enable EIGRP on the interface with the ipv6 eigrp asn interface subcommand (where the asn matches the ipv6 router eigrp asn global configuration command).
Step 5. Enable EIGRP for IPv6 with a no shutdown command while in EIGRP configuration mode, if EIGRP is currently disabled.
Step 6. If no EIGRP router ID has been automatically chosen, because of not having at least one working interface with an IPv4 address, configure an EIGRP router ID with the router-id rid command in EIGRP configuration mode.
The first four steps essentially mirror the four steps in the RIPng configuration process discussed in Chapter 3, “IPv6 Review and RIPng.” The same interdependencies exist for EIGRP for IPv6 as well. Specifically, the command at Step 2 works only if Step 1’s command has been configured, and the command at Step 4 fails if the command at Step 3 has not yet been completed.
EIGRP for IPv6 might also require Steps 5 and 6, whereas RIPng does not need equivalent steps. First, at Step 5, Cisco IOS supports the ability to stop and start the EIGRP process with the shutdown and no shutdown router mode subcommands.
Step 6 shows the other difference as compared to RIPng configuration, but this step might or might not be needed. The EIGRP for IPv6 process must have a router ID (RID) before the process works. EIGRP for IPv6 uses the same process as EIGRP for IPv4 for choosing the RID. The EIGRP for IPv6 RID is indeed a 32-bit number. The following list defines how EIGRP for IPv6 picks its RID, listed in the order of preference:
Step 1. Use the configured value (using the router-id a.b.c.d EIGRP subcommand under the ipv6 router eigrp configuration mode).
Step 2. Use the highest IPv4 address on an up/up loopback interface.
Step 3. Use the highest IPv4 address on an up/up nonloopback interface.
Note that although most installations already have IPv4 addresses configured, it is possible that the EIGRP for IPv6 process cannot derive an RID value. If the router has no working interfaces that have IPv4 addresses, and the EIGRP for IPv6 RID is not explicitly configured, the EIGRP for IPv6 process simply does not work. So, the six-step configuration process includes a mention of the EIGRP RID. More generally, it might be prudent to configure an RID explicitly as a matter of habit.
After being enabled on an interface, EIGRP for IPv6 performs the same two basic tasks as it does with EIGRP for IPv4: It discovers neighbors and advertises connected subnets. EIGRP for IPv6 uses the same set of neighbor checks as do routers using EIGRP for IPv4, except that EIGRP for IPv6 does not require that neighboring IPv6 routers have IPv6 addresses in the same subnet. Also, as with EIGRP for IPv4, EIGRP for IPv6 advertises any and all connected subnets on an interface, with the exception of the link-local addresses and the local routes (the host routes for a router’s own interface IPv6 addresses).
Example 6-1 shows a sample configuration on Router R1 from Figure 6-1. All neighboring routers must use the same ASN; ASN 9 will be used in this case.
Figure 6-1 Sample Internetwork for IPv6 Routing Protocol Configuration
Example 6-1 Configuring EIGRP for IPv6 Routing on R1
R1# show running-config
! output is edited to remove lines not pertinent to this example
! Configuration step 1: enabling IPv6 routing
ipv6 unicast-routing
! Next, configuration steps 3 and 4, on 5 different interfaces
interface FastEthernet0/0.1
ipv6 address 2012::1/64
ipv6 eigrp 9
!
interface FastEthernet0/0.2
ipv6 address 2017::1/64
ipv6 eigrp 9
!
interface FastEthernet0/1.18
ipv6 address 2018::1/64
ipv6 eigrp 9
!
interface Serial0/0/0.3
ipv6 address 2013::1/64
ipv6 eigrp 9
!
interface Serial0/0/0.4
ipv6 address 2014::1/64
ipv6 eigrp 9
!
interface Serial0/0/0.5
ipv6 address 2015::1/64
ipv6 eigrp 9
!
! Configuration steps 2, 5, and 6
ipv6 router eigrp 9
no shutdown
router-id 10.10.34.3
Verifying EIGRP for IPv6
The EIGRP for IPv6 show commands generally list the same kinds of information as the equivalent commands for EIGRP for IPv4, even more so than RIPng. In most cases, simply use the same show ip... commands applicable with IPv4 and EIGRP, and substitute ipv6 for ip. Table 6-3 lists a cross-reference comparing popular EIGRP-related commands for both versions. Note that the table assumes that the commands begin with either show ip or show ipv6 in all but the last row of the table.
Table 6-3 Comparing EIGRP Verification Commands: show ip... and show ipv6...
Example 6-2 shows a few sample show commands taken from Router R3 in the internetwork shown in Figure 6-1. The explanatory comments are listed within the example.
Example 6-2 IPv6 EIGRP show Commands
! On R3, as when using RIPng, the next-hop address is the
! link-local address of the next router.
R3# show ipv6 route 2099::/64
Routing entry for 2099::/64
Known via "eigrp 9", distance 90, metric 2174976, type internal
Route count is 2/2, share count 0
Routing paths:
FE80::22FF:FE22:2222, Serial0/0/0.2
Last updated 00:24:32 ago
FE80::11FF:FE11:1111, Serial0/0/0.1
Last updated 00:07:51 ago
! Note that the next command lists only EIGRP-learned routes. It lists
! two next-hops for 2099::64. Note the next-hop information lists
! link-local addresses.
R3# show ipv6 route eigrp
IPv6 Routing Table - Default - 19 entries
Codes: C - Connected, L - Local, S - Static, U - Per-user Static route
B - BGP, M - MIPv6, R - RIP, I1 - ISIS L1
I2 - ISIS L2, IA - ISIS interarea, IS - ISIS summary, D - EIGRP
EX - EIGRP external
O - OSPF Intra, OI - OSPF Inter, OE1 - OSPF ext 1, OE2 - OSPF ext 2
ON1 - OSPF NSSA ext 1, ON2 - OSPF NSSA ext 2
D 2005::/64 [90/2684416]
via FE80::11FF:FE11:1111, Serial0/0/0.1
via FE80::22FF:FE22:2222, Serial0/0/0.2
D 2012::/64 [90/2172416]
via FE80::22FF:FE22:2222, Serial0/0/0.2
via FE80::11FF:FE11:1111, Serial0/0/0.1
D 2014::/64 [90/2681856]
via FE80::11FF:FE11:1111, Serial0/0/0.1
D 2015::/64 [90/2681856]
via FE80::11FF:FE11:1111, Serial0/0/0.1
! lines omitted for brevity...
D 2099::/64 [90/2174976]
via FE80::22FF:FE22:2222, Serial0/0/0.2
via FE80::11FF:FE11:1111, Serial0/0/0.1
! show ipv6 protocols displays less info than its IPv4 cousin.
R3# show ipv6 protocols
IPv6 Routing Protocol is "eigrp 9"
EIGRP metric weight K1=1, K2=0, K3=1, K4=0, K5=0
EIGRP maximum hopcount 100
EIGRP maximum metric variance 1
Interfaces:
FastEthernet0/0
Serial0/0/0.1
Serial0/0/0.2
Redistribution:
None
Maximum path: 16
Distance: internal 90 external 170
! This command lists the equivalent of the information in the
! show ip protocols commands' "Routing Information Sources" heading.
! Note the link-local addresses are listed.
R3# show ipv6 eigrp neighbors
IPv6-EIGRP neighbors for process 9
H Address Interface Hold Uptime SRTT RTO Q Seq
(sec) (ms) Cnt Num
1 Link-local address: Se0/0/0.2 14 01:50:51 3 200 0 82
FE80::22FF:FE22:2222
0 Link-local address: Se0/0/0.1 13 01:50:52 14 200 0 90
FE80::11FF:FE11:1111
! The next command lists the EIGRP topology database, including
! feasible distance calculations, reported distance, and listing
! all successor and feasible successor routes.
R3# show ipv6 eigrp topology
IPv6-EIGRP Topology Table for AS(9)/ID(10.10.34.3)
Codes: P - Passive, A - Active, U - Update, Q - Query, R - Reply,
r - reply Status, s - sia Status
P 2005::/64, 2 successors, FD is 2684416
via FE80::11FF:FE11:1111 (2684416/2172416), Serial0/0/0.1
via FE80::22FF:FE22:2222 (2684416/2172416), Serial0/0/0.2
P 2012::/64, 2 successors, FD is 2172416
via FE80::11FF:FE11:1111 (2172416/28160), Serial0/0/0.1
via FE80::22FF:FE22:2222 (2172416/28160), Serial0/0/0.2
P 2013::/64, 1 successors, FD is 2169856
via Connected, Serial0/0/0.1
! lines omitted for brevity
P 2099::/64, 2 successors, FD is 2174976
via FE80::11FF:FE11:1111 (2174976/30720), Serial0/0/0.1
via FE80::22FF:FE22:2222 (2174976/30720), Serial0/0/0.2
! Finally, the link-local address of neighbor R1 is identified.
R3# show cdp entry R1
————————————-
Device ID: R1
Entry address(es):
IP address: 10.10.13.1
IPv6 address: 2013::1 (global unicast)
IPv6 address: FE80::11FF:FE11:1111 (link-local)
Platform: Cisco 1841, Capabilities: Router Switch IGMP
Interface: Serial0/0/0.1, Port ID (outgoing port): Serial0/0/0.3
! lines omitted for brevity
The most notable fact listed in the example is that the output confirms that little difference exists with the show commands for EIGRP for IPv4 versus IPv6. The main differences relate to the show ip protocols/show ipv6 protocols commands and that EIGRP for IPv6 uses a link-local IP address for the next hop of each route.
Named EIGRP
Configuring EIGRP for a simple topology that needs few if any parameters changed from their default settings is a fairly simple task. However, consider a router that needs one EIGRP instance to support IPv4 networks and another EIGRP instance to support IPv6 networks. Also, imagine that you want to adjust the default timers, configure the variance option, summarize addresses, and specify a router ID. Suddenly, EIGRP configuration becomes much more challenging, and you are required to jump back and forth between different configuration modes (that is, interface configuration mode, EIGRP for IPv4 configuration mode, and EIGRP for IPv6 configuration mode).
Fortunately, Named EIGRP consolidates all of these disparate commands under a single hierarchical structure, as depicted in Figure 6-2. By having all EIGRP-related commands in one place, not only is configuration simplified, but troubleshooting is also more efficient.
Figure 6-2 Conceptual View of Named EIGRP
This section describes Named EIGRP’s hierarchical structure. Also, to illustrate the difference in the traditional and Named EIGRP configuration approaches, an example of each approach is provided, both of which accomplish the same objectives.
The Named EIGRP Hierarchical Structure
Although Named EIGRP is configured very differently from traditional EIGRP, the configurations are compatible, meaning that an EIGRP-speaking router configured with the traditional approach can form a neighborship with an EIGRP-speaking router configured with the Named approach. Named EIGRP’s hierarchical structure consists of three primary configuration modes. Table 6-4 identifies and describes these modes.
Table 6-4 Configuration Modes of Named EIGRP
Note
Named EIGRP also has Service-Family and Service-Family-Interface configuration modes, similar to the Address-Family and Address-Family-Interface configuration modes. The service family modes are used when EIGRP is advertising a service, using the Service Advertisement Framework (SAF) feature. For example, the Call Control Discovery (CCD) service uses SAF to advertise dial plan information (as opposed to IP route information) for unified communications networks. However, the ROUTE course only focuses on address families.
The following steps can be used to configure Named EIGRP:
Step 1. Configure a Named EIGRP virtual instance using the router eigrp virtual-instance-name command in global configuration mode. It is under this single virtual instance that all address families are configured.
Step 2. Specify an address family along with an autonomous system number using the address-family {ipv4 | ipv6} autonomous-system asn command.
Step 3. Configure general EIGRP settings under Address-Family configuration mode. Examples of commands issued in this configuration mode include metric, network, eigrp stub, and eigrp router-id.
Step 4. (Optional) Enter Address-Family-Interface configuration mode, with the command af-interface {default | interface-id}. If you specify the default option, commands entered in this configuration mode apply to all interfaces (unless overridden by a command applied to a specific interface). Examples of commands issued in this configuration mode include authentication, bandwidth-percent, hello-interval, hold-time, passive-interface, and split-horizon.
Step 5. (Optional) Exit Address-Family-Interface configuration mode (if currently in that mode) with the exit command, and enter Address-Family-Topology configuration mode with the topology base command. Examples of commands issued in the Address-Family-Topology configuration mode include auto-summary, maximum-paths, redistribute, and variance.
To better understand the structure of a Named EIGRP configuration, the next part of this section contrasts a couple of traditional EIGRP configurations with Named EIGRP configurations.
Traditional EIGRP and Named EIGRP Configurations Compared
If a network does not have any special EIGRP requirements (for example, load balancing or summarization), many network administrators configure EIGRP by simply starting an EIGRP routing process and instructing all interfaces to participate in EIGRP. For example, using the topology seen in Figure 6-3, Example 6-3 shows a basic EIGRP for IPv4 configuration using the traditional configuration approach.
Figure 6-3 EIGRP for IPv4 Sample Topology
Example 6-3 Basic EIGRP Configuration Using the Traditional Configuration Approach
!Router R1 Configuration
R1# conf term
R1(config)# router eigrp 1
R1(config-router)# network 0.0.0.0
!Router R2 Configuration
R2# conf term
R2(config)# router eigrp 1
R2(config-router)# network 0.0.0.0
The configuration in Example 6-3 is very straightforward. It enters router configuration mode with the router eigrp asn command and instructs all router interfaces to participate in that EIGRP autonomous system with the command network 0.0.0.0. Example 6-4, still using the topology inFigure 6-3, accomplishes the same result using the Named EIGRP configuration approach.
Example 6-4 Basic EIGRP Configuration Using the Named Configuration Approach
!R1 Router Configuration
R1# conf term
R1(config)# router eigrp R1DEMO
R1(config-router)# address-family ipv4 autonomous-system 1
R1(config-router-af)# network 0.0.0.0
!R2 Router Configuration
R2# conf term
R2(config)# router eigrp R2DEMO
R2(config-router)# address-family ipv4 autonomous-system 1
R2(config-router-af)# network 0.0.0.0
Although still very straightforward, the configuration seen in Example 6-4 is just a bit longer than the configuration seen in Example 6-3. However, the benefit of the Named EIGRP configuration approach becomes more evident when EIGRP has more complex requirements.
For example, consider Example 6-5. It uses the traditional EIGRP configuration approach to meet the following requirements for both Routers R1 and R2 in Figure 6-4:
All interfaces should participate in EIGRP for IPv4 AS 1.
All interfaces should participate in EIGRP for IPv6 AS 2.
The variance option should be set to 2 for both autonomous systems.
The Hello Interval should be set to 2 seconds for EIGRP for IPv4 AS1.
The Hold Time should be set to 10 seconds for EIGRP for IPv4 AS1.
Figure 6-4 EIGRP for IPv4 and EIGRP for IPv6 Sample Topology
Example 6-5 Advanced EIGRP Configuration Using the Traditional Configuration Approach
!Router R1 Configuration
interface FastEthernet0/0
ip address 172.16.1.1 255.255.255.0
ipv6 address 2001::1/64
ipv6 eigrp 2
!
interface Serial1/0
ip address 10.1.1.1 255.255.255.252
ip hello-interval eigrp 1 2
ip hold-time eigrp 1 10
ipv6 address 2002::1/64
ipv6 eigrp 2
!
router eigrp 1
variance 2
network 0.0.0.0
passive-interface default
no passive-interface Serial1/0
!
ipv6 router eigrp 2
variance 2
!Router R2 Configuration
interface FastEthernet0/0
ip address 192.168.1.1 255.255.255.0
ipv6 address 2003::1/64
ipv6 eigrp 2
!
interface Serial1/0
ip address 10.1.1.2 255.255.255.252
ip hello-interval eigrp 1 2
ip hold-time eigrp 1 10
ipv6 address 2002::2/64
ipv6 eigrp 2
!
router eigrp 1
variance 2
network 0.0.0.0
passive-interface default
no passive-interface Serial1/0
!
ipv6 router eigrp 2
variance 2
Using the same topology, Example 6-6 meets the previously stated goals; however, Example 6-6 uses the Named EIGRP configuration approach.
Example 6-6 Advanced EIGRP Configuration Using the Named Configuration Approach
!Router R1 Configuration
router eigrp R1DEMO
!
address-family ipv4 unicast autonomous-system 1
!
af-interface default
hello-interval 2
hold-time 10
passive-interface
exit-af-interface
!
af-interface Serial1/0
no passive-interface
exit-af-interface
!
topology base
variance 2
exit-af-topology
network 0.0.0.0
exit-address-family
!
address-family ipv6 unicast autonomous-system 2
!
topology base
variance 2
exit-af-topology
exit-address-family
!Router R2 Configuration
interface FastEthernet0/0
ip address 192.168.1.1 255.255.255.0
ipv6 address 2003::1/64
!
interface Serial1/0
ip address 10.1.1.2 255.255.255.252
ipv6 address 2002::2/64
!
router eigrp R2DEMO
!
address-family ipv4 unicast autonomous-system 1
!
af-interface default
hello-interval 2
hold-time 10
passive-interface
exit-af-interface
!
af-interface Serial1/0
no passive-interface
exit-af-interface
!
topology base
variance 2
exit-af-topology
network 0.0.0.0
exit-address-family
!
address-family ipv6 unicast autonomous-system 2
!
topology base
variance 2
exit-af-topology
exit-address-family
In the Named EIGRP configuration, notice that each router has a single EIGRP virtual instance, and the EIGRP virtual instance on each router includes two address families, one for IPv4 and one for IPv6. Also notice that each of the configuration commands required to meet the objectives is logically organized under an appropriate configuration mode of the Named EIGRP hierarchy.
Verifying Named EIGRP
Even though Named EIGRP is configured differently than traditional EIGRP, the verification commands remain the same. To illustrate, consider Example 6-7, which shows the output (on Router R1) from a collection of common EIGRP troubleshooting commands.
Example 6-7 Verifying a Named EIGRP Configuration
R1# show ip protocols
*** IP Routing is NSF aware ***
Routing Protocol is "eigrp 1"
Outgoing update filter list for all interfaces is not set
Incoming update filter list for all interfaces is not set
Default networks flagged in outgoing updates
Default networks accepted from incoming updates
EIGRP-IPv4 VR(R1DEMO) Address-Family Protocol for AS(1)
Metric weight K1=1, K2=0, K3=1, K4=0, K5=0 K6=0
Metric rib-scale 128
Metric version 64bit
NSF-aware route hold timer is 240
Router-ID: 172.16.1.1
Topology : 0 (base)
Active Timer: 3 min
Distance: internal 90 external 170
Maximum path: 4
Maximum hopcount 100
Maximum metric variance 2
Total Prefix Count: 3
Total Redist Count: 0
Automatic Summarization: disabled
Maximum path: 4
Routing for Networks:
0.0.0.0
Passive Interface(s):
FastEthernet0/0
Routing Information Sources:
Gateway Distance Last Update
10.1.1.2 90 01:18:03
Distance: internal 90 external 170
R1# show ip eigrp interfaces
EIGRP-IPv4 VR(R1DEMO) Address-Family Interfaces for AS(1)
Xmit Queue PeerQ Mean Pacing Time Multicast Pending
Interface Peers Un/Reliable Un/Reliable SRTT Un/Reliable Flow Timer Routes
Se1/0 1 0/0 0/0 81 0/16 352 0
R1# show ip eigrp interfaces detail s1/0
EIGRP-IPv4 VR(R1DEMO) Address-Family Interfaces for AS(1)
Xmit Queue PeerQ Mean Pacing Time Multicast Pending
Interface Peers Un/Reliable Un/Reliable SRTT Un/Reliable Flow Timer Routes
Se1/0 1 0/0 0/0 81 0/16 352 0
Hello-interval is 2, Hold-time is 10
Split-horizon is enabled
Next xmit serial <none>
Packetized sent/expedited: 2/0
Hello's sent/expedited: 2980/2
Un/reliable mcasts: 0/0 Un/reliable ucasts: 3/3
Mcast exceptions: 0 CR packets: 0 ACKs suppressed: 0
Retransmissions sent: 0 Out-of-sequence rcvd: 0
Topology-ids on interface - 0
Authentication mode is not set
R1# show ipv6 protocols
IPv6 Routing Protocol is "connected"
IPv6 Routing Protocol is "ND"
IPv6 Routing Protocol is "eigrp 2"
EIGRP-IPv6 VR(R1DEMO) Address-Family Protocol for AS(2)
Metric weight K1=1, K2=0, K3=1, K4=0, K5=0 K6=0
Metric rib-scale 128
Metric version 64bit
NSF-aware route hold timer is 240
Router-ID: 172.16.1.1
Topology : 0 (base)
Active Timer: 3 min
Distance: internal 90 external 170
Maximum path: 16
Maximum hopcount 100
Maximum metric variance 2
Total Prefix Count: 3
Total Redist Count: 0
Interfaces:
FastEthernet0/0
Serial1/0
Redistribution:
None
The verification commands demonstrated in Example 6-7 confirm that the previously stated design goals have all been satisfied by the Named EIGRP configuration presented in Example 6-6.
Exam Preparation Tasks
Planning Practice
The CCNP ROUTE exam expects test takers to review design documents, create implementation plans, and create verification plans. This section provides some exercises that can help you to take a step back from the minute details of the topics in this chapter so that you can think about the same technical topics from the planning perspective.
For each planning practice table, simply complete the table. Note that any numbers in parentheses represent the number of options listed for each item in the solutions in Appendix F, “Completed Planning Practice Tables.”
Design Review Table
Table 6-5 lists several design goals related to this chapter. If these design goals were listed in a design document, and you had to take that document and develop an implementation plan, what implementation options come to mind? For any configuration items, a general description can be used, without concern about the specific parameters.
Table 6-5 Design Review
Implementation Plan Peer Review Table
Table 6-6 shows a list of questions that others might ask, or that you might think about, during a peer review of another network engineer’s implementation plan. Complete the table by answering the questions.
Table 6-6 Notable Questions from This Chapter to Consider During an Implementation Plan Peer Review
Create an Implementation Plan Table
To practice skills useful when creating your own OSPF implementation plan, list in Table 6-7 configuration commands related to the configuration of the following features. You might want to record your answers outside the book, and set a goal to complete this table (and others like it) from memory during your final reviews before taking the exam.
Table 6-7 Implementation Plan Configuration Memory Drill
Choose Commands for a Verification Plan Table
To practice skills useful when creating your own OSPF verification plan, list in Table 6-8 all commands that supply the requested information. You might want to record your answers outside the book, and set a goal to complete this table (and others like it) from memory during your final reviews before taking the exam.
Table 6-8 Verification Plan Memory Drill
Note
Some of the entries in this table may not have been specifically mentioned in this chapter but are listed in this table for review and reference.
Review All the Key Topics
Review the most important topics from inside the chapter, noted with the Key Topic icon in the outer margin of the page. Table 6-9 lists a reference of these key topics and the page numbers on which each is found.
Table 6-9 Key Topics for Chapter 6
Complete the Tables and Lists from Memory
Print a copy of Appendix D, “Memory Tables,” (found on the CD) or at least the section for this chapter, and complete the tables and lists from memory. Appendix E, “Memory Tables Answer Key,” also on the CD, includes completed tables and lists to check your work.
Define Key Terms
Define the following key terms from this chapter, and check your answers in the glossary.
EIGRP for IPv6
Named EIGRP
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