multilinking e1 lines and runing eigrp

carl_townshend · ‎01-26-2009

Hi all

If I have 2 e1 lines and want to run eigrp on them, would I create a loopback on the router, then give the physical interaces ipunnumbered loopback 0, then multilink them, would eigrp see them as 1 link on the other side ?

Giuseppe Larosa · ‎01-26-2009

Hello Carl,

almost correct but if you create a PPP multilink all L3 configuration goes under interface multilink:

int ser0/0

no ip addr

enc ppp

ppp multilink 1

int ser0/1

no ip addr

enc ppp

ppp multilink 1

int multilink 1

enc ppp

ppp multilink 1

ip address unnumbered loop0 | ip address x.x.x.1 255.255.255.252

personally I would give an ip address to the multilink on both sides using an ip subnet /30.

to be able to build EIGP adjacency when using ip unnumbered loop0 some more tuning may be needed

Hope to help

Giuseppe

carl_townshend · ‎01-26-2009

hi

can you tell me why the command ppp multilink 1 is in the multilink interface?

also why would it need tuning? do you mean putting a bandwidth statement on the loopback interface?

Giuseppe Larosa · ‎01-26-2009

Hello Carl,

the correct part of my post is that you need to use the multilink interface and you cannot bundle and at the same time assign an ip address (directly or via ip unnumbered ) to member links

about tuning, my concerns are about the capability to build the EIGRP adjacency if the loopback ip addresses are not in the same subnet (if you use /32).

For this reason I recommend to give an ip address to the multilink that is a setup I've already used successfully

for PPP multilink see

http://www.cisco.com/en/US/docs/ios/dial/configuration/guide/dia_media-ind_multi_ppp_ps6922_TSD_Products_Configuration_Guide_Chapter.html#wp1022210

the key commands are

ppp multilink

and

ppp multilink group group-number

in this my example on the fly is wrong

Sorry for this

Hope to help

Giuseppe