IPv6 redistribution ISIS/EIGRP problem

[Gary Lefebvre]

Hello everyone, I have a six router lab that consists of Protocol A (EIGRPv6) and Protocol B (ISIS). When I perform mutual redistribution the EIGRPv6 routes are being passed into Protocol B, but the mutual redistribution of ISIS routes into Protocol A are not passing through. From what I understand of redistribution is that the router will look at its routing table for that protocol and redistribute those routes. Why the routes from ISIS is not not being allowed through is my question. Attached is the "show ipv6 route"'s

EIGRPv6 "show ipv6 route eigrp"

R1#show ipv6 route eigrp
IPv6 Routing Table - default - 15 entries
Codes: C - Connected, L - Local, S - Static, U - Per-user Static route
       B - BGP, HA - Home Agent, MR - Mobile Router, R - RIP
       I1 - ISIS L1, I2 - ISIS L2, IA - ISIS interarea, IS - ISIS summary
       D - EIGRP, EX - EIGRP external, NM - NEMO, ND - Neighbor Discovery
       l - LISP
       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   2001:7052:E1CC:5555::/64 [90/156160]
     via FE80::5, FastEthernet0/0
D   2001:7052:E1CC:6666::/64 [90/156160]
     via FE80::6, FastEthernet0/0
R1#

ISIS "show ipv6 route isis"

R1#show ipv6 route isis
IPv6 Routing Table - default - 15 entries
Codes: C - Connected, L - Local, S - Static, U - Per-user Static route
       B - BGP, HA - Home Agent, MR - Mobile Router, R - RIP
       I1 - ISIS L1, I2 - ISIS L2, IA - ISIS interarea, IS - ISIS summary
       D - EIGRP, EX - EIGRP external, NM - NEMO, ND - Neighbor Discovery
       l - LISP
       O - OSPF Intra, OI - OSPF Inter, OE1 - OSPF ext 1, OE2 - OSPF ext 2
       ON1 - OSPF NSSA ext 1, ON2 - OSPF NSSA ext 2
I2  ::/0 [115/10]
     via FE80::3, Serial0/0/1
I1  2001:7052:E1CC:2222::/64 [115/20]
     via FE80::2, Serial0/0/0
I1  2001:7052:E1CC:3333::/64 [115/20]
     via FE80::3, Serial0/0/1
I1  2001:7052:E1CC:A023::/64 [115/20]
     via FE80::3, Serial0/0/1
     via FE80::2, Serial0/0/0
R1#

Redistributed routes on R2

R2#show ipv6 route isis
IPv6 Routing Table - default - 14 entries
Codes: C - Connected, L - Local, S - Static, U - Per-user Static route
       B - BGP, HA - Home Agent, MR - Mobile Router, R - RIP
       I1 - ISIS L1, I2 - ISIS L2, IA - ISIS interarea, IS - ISIS summary
       D - EIGRP, EX - EIGRP external, NM - NEMO, ND - Neighbor Discovery
       l - LISP
       O - OSPF Intra, OI - OSPF Inter, OE1 - OSPF ext 1, OE2 - OSPF ext 2
       ON1 - OSPF NSSA ext 1, ON2 - OSPF NSSA ext 2
I2  ::/0 [115/10]
     via FE80::3, Serial0/0/1
I2  2001:7052:E1CC:156::/64 [115/11]
     via FE80::1, Serial0/0/0
I1  2001:7052:E1CC:1111::/64 [115/20]
     via FE80::1, Serial0/0/0
I1  2001:7052:E1CC:3333::/64 [115/20]
     via FE80::3, Serial0/0/1
I2  2001:7052:E1CC:5555::/64 [115/11]
     via FE80::1, Serial0/0/0
I2  2001:7052:E1CC:6666::/64 [115/11]
     via FE80::1, Serial0/0/0
I1  2001:7052:E1CC:A013::/64 [115/20]
     via FE80::3, Serial0/0/1
     via FE80::1, Serial0/0/0
R2#

Redistributed routes on R5

R5#show ipv6 route eigrp                                                     
IPv6 Routing Table - default - 6 entries
Codes: C - Connected, L - Local, S - Static, U - Per-user Static route
       B - BGP, HA - Home Agent, MR - Mobile Router, R - RIP
       D - EIGRP, EX - EIGRP external, NM - NEMO, ND - Neighbor Discovery
       l - LISP
       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   2001:7052:E1CC:6666::/64 [90/156160]
     via FE80::6, FastEthernet0
R5#

R1#config

!
!
!

!
! Last configuration change at 23:27:36 UTC Wed Oct 28 2015
!
version 15.2
service timestamps debug datetime msec
service timestamps log datetime msec
!
hostname R1
!
boot-start-marker
boot-end-marker
!
!
!
no aaa new-model
no ip icmp rate-limit unreachable
!
!
!
!
!
!
no ip domain lookup
ip cef
ipv6 unicast-routing
ipv6 cef
!
!
multilink bundle-name authenticated
!
!
!
!
!
!
!
!
!
!
!
!
ip tcp synwait-time 5
!
!
!
!
!
!
!
!
!
interface Loopback0
 no ip address
 ipv6 address 2001:7052:E1CC:1111::1/64
 ipv6 router isis 123
!
interface FastEthernet0/0
 no ip address
 duplex full
 ipv6 address FE80::1 link-local
 ipv6 address 2001:7052:E1CC:156::1/64
 ipv6 eigrp 123
!
interface Serial1/0
 no ip address
 ipv6 address FE80::1 link-local
 ipv6 address 2001:7052:E1CC:A012::1/64
 ipv6 router isis 123
 serial restart-delay 0
 clock rate 64000
!
interface Serial1/1
 no ip address
 ipv6 address FE80::1 link-local
 ipv6 address 2001:7052:E1CC:A013::1/64
 ipv6 router isis 123
 serial restart-delay 0
!
interface Serial1/2
 no ip address
 shutdown
 serial restart-delay 0
!
interface Serial1/3
 no ip address
 shutdown
 serial restart-delay 0
!
interface Serial1/4
 no ip address
 shutdown
 serial restart-delay 0
!
interface Serial1/5
 no ip address
 shutdown
 serial restart-delay 0
!
interface Serial1/6
 no ip address
 shutdown
 serial restart-delay 0
!
interface Serial1/7
 no ip address
 shutdown
 serial restart-delay 0
!
interface Ethernet2/0
 no ip address
 shutdown
 duplex full
!
interface Ethernet2/1
 no ip address
 shutdown
 duplex full
!
interface Ethernet2/2
 no ip address
 shutdown
 duplex full
!
interface Ethernet2/3
 no ip address
 shutdown
 duplex full
!
interface Ethernet2/4
 no ip address
 shutdown
 duplex full
!
interface Ethernet2/5
 no ip address
 shutdown
 duplex full
!
interface Ethernet2/6
 no ip address
 shutdown
 duplex full
!
interface Ethernet2/7
 no ip address
 shutdown
 duplex full
!
router isis 123
 net 49.0123.0000.0000.0001.00
 !
 address-family ipv6
  redistribute eigrp 123 metric 1 include-connected
 exit-address-family
!
ip forward-protocol nd
!
!
no ip http server
no ip http secure-server
!
ipv6 router eigrp 123
 eigrp router-id 10.1.1.1
 redistribute isis 123 level-1-2 metric 1 1 1 1 1 include-connected
!
!
!
!
control-plane
!
!
line con 0
 exec-timeout 0 0
 privilege level 15
 logging synchronous
 stopbits 1
line aux 0
 exec-timeout 0 0
 privilege level 15
 logging synchronous
 stopbits 1
line vty 0 4
 login
!
!
end

[Peter Paluch]

Gary,

Just a hunch - can you perhaps configure R1 to use more sensible EIGRP metrics when redistributing the routes? Your metrics of "1 1 1 1 1" result into very high composite metric (primarily caused by a very low bandwidth), and it is possible that at some point in the network, the resulting composite metrics just reach the maximum possible value.

Would this work instead on R1?

ipv6 router eigrp 123
 eigrp router-id 10.1.1.1
 redistribute isis 123 level-1-2 metric 100000 1 255 1 1500 include-connected

In addition, can you check the output of show ipv6 eigrp topology on R1 to see if the routes get redistributed from ISIS into EIGRP at least locally?

Best regards,
Peter

[Gary Lefebvre]

Peter, you gave me the most logical explanation to the problem. I thought for sure this was the answer, but I am having the same issue after making this change. The ISIS routes are not being redistributed into the EIGRPv6 domain...

king regards!

[Peter Paluch · Accepted solution]

Gary,

Okay, I've labbed this up. I don't know if it is a limitation or an intentional "feature" but it looks like EIGRP is unable to redistribute IS-IS routes if the IS-IS process has been configured with an area tag. Actually this is what you did - you have configured IS-IS with an area tag of "123". However, the area tag should not be used unless you know precisely why you need it (either for VRF-bound processes or for so-called multiarea IS-IS which is a relatively strange feature to not bother with it at this point).

The redistribution will work if you call your IS-IS process simply as router isis and activate it on your interfaces with ipv6 router isis and also in EIGRPv6 configuration, you start the redistribution with redistribute isis level-1-2 include connected metric 100000 1 255 1 1500 command - omitting the area tag 123 everywhere.

Try this out!

Best regards,
Peter

[Gary Lefebvre]

Yes Peter, this solved my problem, YES! I am not very informed on using ISIS only enough to get by. Thank you so much!

i ran the other protocol mutual redistribution using the area tag and had no problems. I redistributed OSPF and RIPNG, all good with the area tag.

i know that ISIS is like OSPF in that they are both Link State protocols.

Thank you, again!

Kind regards

[Peter Paluch]

Hi Gary,

I am glad this has helped.

With OSPF and RIPng, those "numbers" were not area tags but rather process identifiers. Those are somewhat different from IS-IS area tags, and yes, those are absolutely supposed to work even in redistribution.

I am trying to find out more what is happening with IS-IS here. It's possible it's a bug, or a feature I haven't seen documented so far.

And yes, you're right, IS-IS and OSPF are both link-state routing protocols and are based on very similar principles.

Best regards,
Peter