I don't think it's an MTU issue, as i'm running the NM-16 module for the
switching function on the GNS3 simulator

 

 

From: Wouter Prins [mailto:[email protected]] 
Sent: Monday, 15 June 2009 12:54 AM
To: Antonio Dee Hotmail
Subject: Re: [OSL | CCIE_RS] Fallback Bridging creating problem with routing
protocol

 

MTU issue?

2009/6/13 Antonio Dee Hotmail <[email protected]>

Hi All,

 

I'm not sure if this is just because of GNS3 or this is really a problem
with Fallback bridging to look out for.

 

My fallback bridging configuration on Cat1 is:

 

Cat1(config)# bridge 10 protocol vlan-bridge

Cat1(config)# no bridge 10 acquire

Cat1(config)# bridge 10 address 1111.1111.1111 forward

Cat1(config)# bridge 10 address aaaa.aaaa.aaaa forward

!

Cat1(config)# int vlan 5

Cat1(config-if)# bridge 10

!

Cat1(config)# int fa1/10

Cat1(config-if)# bridge 10 

 

Nothing fancy, I'm just trying out scenarios integrating different things to
see if they break or not. And i stumbled something that breaks :-) or :-(

 

My setup is so simple:    R10 <-------> Cat1 <------> R5

 

R10 (192.168.10.10) to Cat1 subnet is 192.168.10.0/24        - Cat1
connected to R10 with Fa1/10 port L3 configuration

R5 (192.168.5.5) to Cat1 subnet is 192.168.5.0/24             - Cat1
connected to R5 with Fa1/5 port L2 configuration (vlan 5) ; SVI on Cat1 is
192.168.5.1

 

Everytime i stop my GNS3 and then start back from scratch, i get this error
after injecting the fallback bridging on Cat1 to bridge both subnets.

 

I get this error on R5 to Cat1 leg, i don't see this on R10 to Cat1 leg.

 

It goes up and then goes down, it's flapping.

 

Cat1(config)#

*Mar  1 00:20:53.703: %DUAL-5-NBRCHANGE: IP-EIGRP(0) 1: Neighbor 192.168.5.5
(Vlan5) is up: new adjacency

Cat1(config)#

*Mar  1 00:22:13.187: %DUAL-5-NBRCHANGE: IP-EIGRP(0) 1: Neighbor 192.168.5.5
(Vlan5) is down: Interface Goodbye received

Cat1(config)#

*Mar  1 00:22:15.999: %DUAL-5-NBRCHANGE: IP-EIGRP(0) 1: Neighbor 192.168.5.5
(Vlan5) is up: new adjacency

Cat1(config)#

*Mar  1 00:23:35.511: %DUAL-5-NBRCHANGE: IP-EIGRP(0) 1: Neighbor 192.168.5.5
(Vlan5) is down: retry limit exceeded

Cat1(config)#

*Mar  1 00:23:38.131: %DUAL-5-NBRCHANGE: IP-EIGRP(0) 1: Neighbor 192.168.5.5
(Vlan5) is down: Interface Goodbye received

Cat1(config)#

*Mar  1 00:23:41.563: %DUAL-5-NBRCHANGE: IP-EIGRP(0) 1: Neighbor 192.168.5.5
(Vlan5) is up: new adjacency

 

 

Cheers!

Antonio




-- 
Wouter Prins
[email protected]
0x301FA912

Reply via email to