Unable to get Bridge-Domain to work on an ISR4351/K9.

[James L]

Hi. I'm having difficulty getting Bridge-Domain to work on my ISR4351/K9 Router.

Topology is as follows:

Router Interface g0/0/1 & 2 will go into a Firewall eventually but for testing I have them connected to a unmanaged hub and my pc is connected to this to create a network.

When I only have 1 link up on the Router (either 1 or 2) I PC can ping the Router no problems but when I connect the 2nd cable I start to get a loop... I know this because interface counters on g0/0/1 & 2 start to increment like crazy up to the 400Mb limit of my Router.

Config is as follows:

bridge-domain 1 

!

bridge irb

!

interface GigabitEthernet0/0/1
description inside
no ip address
load-interval 30
negotiation auto
service instance 1 ethernet
encapsulation untagged
bridge-domain 1
!
interface GigabitEthernet0/0/2
description inside
no ip address
load-interval 30
negotiation auto
service instance 1 ethernet
encapsulation untagged
bridge-domain 1

!

interface BDI1
ip address 123.123.123.1 255.255.255.0

Must be missing something really simple!

Anybody help will be greatly appreciated.

TIA.

[Julio E. Moisa]

Hi

Try with this configuration:

bridge irb

bridge 1 protocol ieee

bridge 1 route ip

interface g0/0/1

bridge-group 1 

interface g0/0/2

bridge-group 1 

interface bvi 1

ip address x.x.x.x y.y.y.y

no shutdown.

The following link can be useful, it includes: BVI and BDI (Bridge domain interface):

https://www.cisco.com/c/en/us/support/docs/lan-switching/integrated-routing-bridging-irb/200650-Understanding-Bridge-Virtual-Interface.html

Hope it is useful

:-)

[James L]

No go :(

I don't have IEEE option type:

Routert(config)#bridge 1 protocol ?
dec DEC protocol
ibm IBM protocol
vlan-bridge vlan-bridge protocol

Router(config)#bridge 1 protocol

And in the Interface I don't have an option to put down 'bridge-group 1'.

My Router is running this IOS:  isr4300-universalk9.03.16.06b.S.155-3.S6b-ext.SPA

So it's an IOS-XE...

If I have only 1 leg up PC can ping the Router but when both legs are up ping times out so probably related to a loop happening?

[Georg Pauwen]

Hello,

on a side note, and I don't know if that output is just omitted, make sure you have your service instance configured as well:

bridge-domain 1
!
bridge irb
!
interface GigabitEthernet0/0/1
description inside
no ip address
load-interval 30
negotiation auto
service instance 1 ethernet
encapsulation untagged
bridge-domain 1
!
interface GigabitEthernet0/0/2
description inside
no ip address
load-interval 30
negotiation auto
service instance 1 ethernet
encapsulation untagged
bridge-domain 1
!
service instance 1 ethernet
bridge-domain 1
!
interface BDI1
ip address 123.123.123.1 255.255.255.0

[James L]

Again no go :( I don't have that as an option...

Router(config)#service-instance ?
mdns-sd Static Service MDNS configuration

[Georg Pauwen]

Hello,

the command is:

Router(config)#service instance 

without the dash. What are your options at:

Router(config)#service ?

[James L]

Router(config)#service ?
alignment Control alignment correction
call-home Enable call-home service
compress-config Compress the nvram configuration file
config TFTP load config files
counters Control aging of interface counters
dhcp Enable DHCP server and relay agent
disable-ip-fast-frag Disable IP particle-based fast fragmentation
exec-callback Enable exec callback
exec-wait Delay EXEC startup on noisy lines
finger Allow responses to finger requests
hide-telnet-addresses Hide destination addresses in telnet command
linenumber enable line number banner for each exec
nagle Enable Nagle's congestion control algorithm
old-slip-prompts Allow old scripts to operate with slip/ppp
pad Enable PAD commands
password-encryption Encrypt system passwords
prompt Enable mode specific prompt
pt-vty-logging Log significant VTY-Async events
sequence-numbers Stamp logger messages with a sequence number
slave-log Enable log capability of slave IPs
tcp-keepalives-in Generate keepalives on idle incoming network connections
tcp-keepalives-out Generate keepalives on idle outgoing network connections
tcp-small-servers Enable small TCP servers (e.g., ECHO)
telnet-zeroidle Set TCP window 0 when connection is idle
timestamps Timestamp debug/log messages
udp-small-servers Enable small UDP servers (e.g., ECHO)

[James L]

Router(config)#service ?
alignment Control alignment correction
call-home Enable call-home service
compress-config Compress the nvram configuration file
config TFTP load config files
counters Control aging of interface counters
dhcp Enable DHCP server and relay agent
disable-ip-fast-frag Disable IP particle-based fast fragmentation
exec-callback Enable exec callback
exec-wait Delay EXEC startup on noisy lines
finger Allow responses to finger requests
hide-telnet-addresses Hide destination addresses in telnet command
linenumber enable line number banner for each exec
nagle Enable Nagle's congestion control algorithm
old-slip-prompts Allow old scripts to operate with slip/ppp
pad Enable PAD commands
password-encryption Encrypt system passwords
prompt Enable mode specific prompt
pt-vty-logging Log significant VTY-Async events
sequence-numbers Stamp logger messages with a sequence number
slave-log Enable log capability of slave IPs
tcp-keepalives-in Generate keepalives on idle incoming network connections
tcp-keepalives-out Generate keepalives on idle outgoing network connections
tcp-small-servers Enable small TCP servers (e.g., ECHO)
telnet-zeroidle Set TCP window 0 when connection is idle
timestamps Timestamp debug/log messages
udp-small-servers Enable small UDP servers (e.g., ECHO)

Router(config)#service

[sp2720401]

"service instance" is configured under the interface.

[James L]

Yes thank you. I have this under my 2 physical interfaces:
service instance 1 ethernet
encapsulation untagged

I think Georg wants me to put this config from under global config mode:

service instance 1 ethernet
bridge-domain 1

But this will not work.

[sp2720401]

service instance isn't a global config. You also don't need "bridge irb"... that is for bridge-groups and BVI interfaces.

This is the bare minumum you need.

bridge-domain 1
!
interface GigabitEthernet0/0/1
no shut
service instance 1 ethernet
encapsulation untagged
bridge-domain 1
!
interface GigabitEthernet0/0/2
no shut
service instance 1 ethernet
encapsulation untagged
bridge-domain 1
!
interface BDI1
ip address 123.123.123.1 255.255.255.0
no shut

Also if you plug both of them into a hub or dumb switch at the same time you are creating an L2 loop which leads to a broadcast storm and your interfaces will eventually not process any traffic because they are 100 percent full with replicated frames.

[James L · Accepted solution]

Ahh it's working!

I had 1 PC connected to G0/0/1 and another on G0/0/2. I could ping each other and the default GW as well (address defined on BDI1).
This is all the Bridge-Domain relevant config that I have in place:

bridge-domain 1
!
interface GigabitEthernet0/0/1
no shut
service instance 1 ethernet
encapsulation untagged
bridge-domain 1
!
interface GigabitEthernet0/0/2
no shut
service instance 1 ethernet
encapsulation untagged
bridge-domain 1
!
interface BDI1
ip address 123.123.123.1 255.255.255.0
no shut

[sp2720401]

So it was a loop problem...

Now you can add all of your bonus features you want on the router.

[James L]

Maybe :)

[Parag@jsvtechnologies.com]

Hi,

I am not getting option of Bridge under GigabitEthernet or Serial Interface. How do I configure Bridge command under any interface.