EIGRP IPv6 - Summarization
Summarization
EIGRP (Enhanced Interior Gateway Routing Protocol) IPv6 Summarization is a strategic technique that optimizes routing tables in an IPv6 network by aggregating multiple contiguous subnets into a single summary route. This process reduces the size of routing updates and enhances network scalability and efficiency. By employing summarization, administrators can effectively minimize the number of routes exchanged between EIGRP routers, conserving bandwidth and memory resources. The 'ipv6 summary-address' command is used to configure IPv6 summarization, specifying the summary route and corresponding subnet mask. Proper summarization requires a careful consideration of the network topology to ensure that it aligns with the summarization boundaries without causing suboptimal routing or connectivity issues. EIGRP IPv6 Summarization is a valuable tool for simplifying and optimizing routing information, particularly in large and complex IPv6 networks, contributing to improved network performance and stability.
Lab:
Disclaimer
This Configuration Guide is designed to assist members to enhance their skills in particular technology area. While every effort has been made to ensure that all material is as complete and accurate as possible, the enclosed material is presented on an Dzas isdz basis. Neither the authors nor Forum assume any liability or responsibility to any person or entity with respect to loss or damages incurred from the information contained in this guide. This configuration guide was developed by Forum. Any similarities between material presented in this configuration guide and any other material is completely coincidental.
Cisco IOS Software, Linux Software (I86BI_LINUX-ADVENTERPRISEK9-M), Version 15.2(4)M1, DEVELOPMENT TEST SOFTWARE
Task 1: Configure IPv6 EIGRP Summarization
Step 1: In the configuration mode of router configure 4 loopbacks with IPv6 network address in sequence
R1:
interface loopback 1
ipv6 address 11:0:0::1/64
exit
interface loopback 2
ipv6 address 11:0:1::1/64
exit
interface loopback 3
ipv6 address 11:0:2::1/64
exit
interface loopback 4
ipv6 address 11:0:3::1/64
exit
Step 2: Disable auto-summarization in IPv6 EIGRP Process & verify IPv6 routes on neighbor routing table
R1:
ipv6 router eigrp 100
no auto-summary
exit
R2#show ipv6 route
IPv6 Routing Table - default - 23 entries
Codes: C - Connected, L - Local, S - Static, U - Per-user Static route
B - BGP, HA - Home Agent, MR - Mobile Router, R - RIP
IS - ISIS summary, D - EIGRP, EX - EIGRP external, NM - NEMO
ON1 - OSPF NSSA ext 1, ON2 - OSPF NSSA ext 2, l - LISP
D 11:0:0::/64 [90/2297856]
via FE80::A8BB:CCFF:FE00:100, Serial2/0
D 11:0:1::/64 [90/2297856]
via FE80::A8BB:CCFF:FE00:100, Serial2/0
D 11:0:2::/64 [90/2297856]
via FE80::A8BB:CCFF:FE00:100, Serial2/0
D 11:0:3::/64 [90/2297856]
via FE80::A8BB:CCFF:FE00:100, Serial2/0
C 12::/64 [0/0]
via Serial2/0, directly connected
L 12::A8BB:CCFF:FE00:200/128 [0/0]
via Serial2/0, receive
C 22:0:0::/64 [0/0]
via Loopback1, directly connected
L 22:0:0::2/128 [0/0]
via Loopback1, receive
C 22:0:1::/64 [0/0]
via Loopback1, directly connected
L 22:0:1::2/128 [0/0]
via Loopback1, receive
C 22:0:2::/64 [0/0]
via Loopback2, directly connected
L 22:0:2::2/128 [0/0]
via Loopback2, receive
C 22:0:3::/64 [0/0]
via Loopback3, directly connected
L 22:0:3::2/128 [0/0]
via Loopback3, receive
C 23::/64 [0/0]
via Ethernet0/0, directly connected
L 23::A8BB:CCFF:FE00:200/128 [0/0]
via Ethernet0/0, receive
D 33:0:0::/64 [90/409600]
via FE80::A8BB:CCFF:FE00:300, Ethernet0/0
D 33:0:1::/64 [90/409600]
via FE80::A8BB:CCFF:FE00:300, Ethernet0/0
D 33:0:2::/64 [90/409600]
via FE80::A8BB:CCFF:FE00:300, Ethernet0/0
D 33:0:3::/64 [90/409600]
via FE80::A8BB:CCFF:FE00:300, Ethernet0/0
D 34::/64 [90/2195456]
via FE80::A8BB:CCFF:FE00:300, Ethernet0/0
D 44:0:0::/64 [90/2835456]
via FE80::A8BB:CCFF:FE00:200, Serial2/0
D 44:0:1::/64 [90/2835456]
via FE80::A8BB:CCFF:FE00:200, Serial2/0
D 44:0:2::/64 [90/2835456]
via FE80::A8BB:CCFF:FE00:200, Serial2/0
D 44:0:3::/64 [90/2835456]
via FE80::A8BB:CCFF:FE00:200, Serial2/0
L FF00::/8 [0/0]
via Null0, receive
Step 3: Summarize IPv6 EIGRP routes on outgoing interface
R1:
interface serial 2/0
ipv6 summary-address 11::/16
exit
Summarization is configurable on a per-interface basis in any router within network. Router R1 sends summary of 11 network on interface s2/0
Task 2: Verification: Step 1: Verify receipt of summary route in neighbors IPv6 routing table by following command:
R2#show ipv6 route
IPv6 Routing Table - default - 20 entries
O - OSPF Intra, OI - OSPF Inter, OE1 - OSPF ext 1, OE2 - OSPF ext 2
ON1 - OSPF NSSA ext 1, ON2 - OSPF NSSA ext 2, l - LISP
D 11::/16 [90/2297856]
via FE80::A8BB:CCFF:FE00:100, Serial2/0
C 12::/64 [0/0]
via Serial2/0, directly connected
L 12::A8BB:CCFF:FE00:200/128 [0/0]
via Serial2/0, receive
C 22:0:1::/64 [0/0]
via Loopback1, directly connected
L 22:0:1::2/128 [0/0]
via Loopback1, receive
C 22:0:2::/64 [0/0]
via Loopback2, directly connected
L 22:0:2::2/128 [0/0]
via Loopback2, receive
C 22:0:3::/64 [0/0]
L 22:0:3::2/128 [0/0]
via Loopback3, receive
C 22:0:4::/64 [0/0]
via Loopback4, directly connected
L 22:0:4::2/128 [0/0]
via Loopback4, receive
C 23::/64 [0/0]
via Ethernet0/0, directly connected
L 23::A8BB:CCFF:FE00:200/128 [0/0]
via Ethernet0/0, receive
D 33:0:1::/64 [90/409600]
via FE80::A8BB:CCFF:FE00:300, Ethernet0/0
D 33:0:2::/64 [90/409600]
via FE80::A8BB:CCFF:FE00:300, Ethernet0/0
D 33:0:3::/64 [90/409600]
via FE80::A8BB:CCFF:FE00:300, Ethernet0/0
D 33:0:4::/64 [90/409600]
via FE80::A8BB:CCFF:FE00:300, Ethernet0/0
D 34::/64 [90/2195456]
via FE80::A8BB:CCFF:FE00:300, Ethernet0/0
D 44::/16 [90/2323456]
via FE80::A8BB:CCFF:FE00:300, Ethernet0/0
L FF00::/8 [0/0]
via Null0, receive
IPv6 Summarized routes is received from neighbor router.
Step 2: Verify creation of null interface in IPv6 routing table
R1#show ipv6 route
IPv6 Routing Table - default - 23 entries
Codes: C - Connected, L - Local, S - Static, U - Per-user Static route
B - BGP, HA - Home Agent, MR - Mobile Router, R - RIP
H - NHRP, I1 - ISIS L1, I2 - ISIS L2, IA - ISIS interarea
IS - ISIS summary, D - EIGRP, EX - EIGRP external, NM - NEMO
ND - ND Default, NDp - ND Prefix, DCE - Destination, NDr - Redirect
O - OSPF Intra, OI - OSPF Inter, OE1 - OSPF ext 1, OE2 - OSPF ext 2
ON1 - OSPF NSSA ext 1, ON2 - OSPF NSSA ext 2, l – LISP
D 11::/16 [5/128256]
via Null0, directly connected
C 11:0:1::/64 [0/0]
via Loopback1, directly connected
L 11:0:1::1/128 [0/0]
via Loopback1, receive
C 11:0:2::/64 [0/0]
via Loopback2, directly connected
L 11:0:2::1/128 [0/0]
via Loopback2, receive
C 11:0:3::/64 [0/0]
via Loopback3, directly connected
L 11:0:3::1/128 [0/0]
via Loopback3, receive
C 11:0:4::/64 [0/0]
via Loopback4, directly connected
L 11:0:4::1/128 [0/0]
via Loopback4, receive
C 12::/64 [0/0]
via Serial2/0, directly connected
L 12::A8BB:CCFF:FE00:100/128 [0/0]
via Serial2/0, receive
D 22:0:1::/64 [90/2297856]
via FE80::A8BB:CCFF:FE00:200, Serial2/0
D 22:0:2::/64 [90/2297856]
via FE80::A8BB:CCFF:FE00:200, Serial2/0
D 22:0:3::/64 [90/2297856]
via FE80::A8BB:CCFF:FE00:200, Serial2/0
D 22:0:4::/64 [90/2297856]
via FE80::A8BB:CCFF:FE00:200, Serial2/0
D 23::/64 [90/2195456]
via FE80::A8BB:CCFF:FE00:200, Serial2/0
D 33:0:1::/64 [90/2323456]
via FE80::A8BB:CCFF:FE00:200, Serial2/0
D 33:0:2::/64 [90/2323456]
via FE80::A8BB:CCFF:FE00:200, Serial2/0
D 33:0:3::/64 [90/2323456]
via FE80::A8BB:CCFF:FE00:200, Serial2/0
D 33:0:4::/64 [90/2323456]
via FE80::A8BB:CCFF:FE00:200, Serial2/0
D 34::/64 [90/2707456]
via FE80::A8BB:CCFF:FE00:200, Serial2/0
D 44::/16 [90/2835456]
via FE80::A8BB:CCFF:FE00:200, Serial2/0
L FF00::/8 [0/0]
via Null0, receive
When summarization is configured on a router, same router immediately created a routing point to Null 0 for loop prevention.