802.3ad

sameermunj · ‎02-19-2009

can i configure 802.3ad for 2 gig ports on cisco 2851 router.Cisco 2851 router connected to 2 different L2 switch with each gig port and each L2 switch is connected to firwall on vertical link.i want my both firewalls and router in single subnet...

Kerem Gursu · ‎02-19-2009

Hi Sameer,

According to the network diagram , I would suggest using Transparent Bridging and using a BVI interface on router. You can find details about this technology at

http://www.cisco.com/en/US/docs/ios/bridging/configuration/guide/br_transprnt_brdg_ps6350_TSD_Products_Configuration_Guide_Chapter.html

Hope to help,

Kerem

Giuseppe Larosa · ‎02-19-2009

Hello Sameer,

I agree with Karem.

an etherchannel makes sense when going to the same device not to two different switches.

If you use IRB one link will be active and used and the second will be ready to be used.

the router will use IEE STP to manage redundancy together with the switches

Hope to help

Giuseppe

sameermunj · ‎02-19-2009

Hi

So looking at the ppt i had attahced in my 1st thread,will the config will look like this

Router# configure terminal

Router(config)# bridge 10 protocol ieee

Router(config)# int Gig 0/0

Router(config-if)# bridge-group 10

Router(config-if)# cut-through

Router(config-if)# no shutdown

Router(config-if)# exit

Router(config)# int Gig 0/1

Router(config-if)# bridge-group 10

Router(config-if)# cut-through

Router(config-if)# no shutdown

Router(config-if)# exit

Router(config)# bridge irb

Router(config)# interface bvi 10

Router(config-if)# ip address 192.168.1.4 255.255.255.248

Router(config-if)# no shutdown

Router(config-if)# exit

Router(config)#

Router(config)# bridge 10 route ip

Router(config)# exit

Router#

Both Firewall will have default route towards 192.168.1.4 and router will point static route for internal networks towards 192.168.1.3 (VRRP IP of firewall)

If Any other option in this case apart from IRB which is purely routing based please let me know

Giuseppe Larosa · ‎02-19-2009

Hello Sameer,

the configuration is correct.

Note:

IRB : integrated routing and bridging is not a purely routing solution

the command bridge 10 protocol ieee starts an STP instance that follows 802.1D.

These BPDUs are exchanged with the two switches and a loop free path is built using 802.1D

Hope to help

Giuseppe