How to configure RIPNG on Cisco IOS Router

(Rene Molenaar) #1

This topic is to discuss the following lesson:

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(Frades) #2

awesome lesson. just a question rene, when we activate the RIP under the interface it does 2 things

Activate the prefix on the interface in RIPNG.
Send RIPNG updates out of this interface.

do we have a passive interface on this? is this the same as RIP or any routing protocol in IPv4 that if the interface is going to your LAN network, it is much better not to Send Routing updates to that interface. We suppressed it by using Passive Interface so that we will only advertise the network on that interface. This is for security purposes right?

Thank you!

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(Rene Molenaar) #3

Hi John,

Good question, the behavior of RIPng is the same as RIP for IPv4. The funny part though is that there is no “passive interface” command for RIPng.

To simulate the same behavior of the passive interface command you can use one of the following two methods:

  1. Don’t enable RIPng on the interface that should be made passive but use “redistribute connect” instead.

  2. Use a prefix-list to filter RIPng advertisements on the interface that should be passive.

It’s a bit lame and I don’t know why passive interface isn’t supported, but this gets you the same result :slight_smile:

Rene

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(Casper V) #4

Hi Rene

Just a question, more of a general IPV6 question, why does a loopback interface generate the same link-local address as the physical interface. Yes I understand that the loopback don’t have it’s own mac address and will use the physical interface, but why doesn’t it cause a conflict on the local device, I was under the impression the link-local address must be unique on the llocal device:

R8#sh ipv6 int brief
Em0/0                  [administratively down/down]
    unassigned
GigabitEthernet0/0     [up/up]
    FE80::6273:5CFF:FEF8:D8E0
GigabitEthernet0/1     [up/up]
    unassigned
Serial0/0/0            [down/down]
    unassigned
Loopback0              [up/up]
    FE80::6273:5CFF:FEF8:D8E0
    2001:DB8::1
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(Rene Molenaar) #5

Hi Casper,

These link-local addresses are only valid on the link and unroutable so that’s why it is no problem to have the same address on multiple interfaces.

Rene

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(Anderson Felipe S) #6

Is it possible to work with summarized routes in the dynamic routing protocol, as well as in static routing?

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(Rene Molenaar) #7

Routing protocols, including RIPNG, support summarization yes.

Here’s how you can do summarization in RIPNG. Right now, R2 only has one entry:

R2#show ipv6 route rip 

R   2001::1/128 [120/2]
     via FE80::F816:3EFF:FE30:91B8, FastEthernet0/0

Summaries are configured on the interface in RIPNG. Let’s try that on R1:

R1(config)#interface GigabitEthernet 0/1
R1(config-if)#ipv6 rip RIPNGTEST summary-address 2001::/64

Here’s the result:

R2#show ipv6 route rip 

R   2001::/64 [120/2]
     via FE80::F816:3EFF:FE30:91B8, FastEthernet0/0
R   2001::1/128 [120/2]
     via FE80::F816:3EFF:FE30:91B8, FastEthernet0/0

You can see the 2001::/64 summary route on R2.

With a static route, we don’t advertise anything so there’s no summary route like in routing protocols.

Rene

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(Hang S) #8

Hi, Rene,

Just wondering what if I manually set different link-local address on the different interface in a router when setup RIPNG, is there any error message popup?

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(Lazaros Agapides) #9

Hello Hang.

If you manually set up different link-local addresses on the interfaces of a router, even if you have RIPNG set up, there shouldn’t be any error messages. This is especially the case with RIPNG because you don’t have any network commands to indicate the subnet on which RIP will be participating. You specifiy the interface on which RIP will be function and this allows you to change the IPv6 address (link local or otherwise) without any problems on your configuration).

I hope this has been helpful!

Laz

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