02-25-2009 11:05 PM - edited 03-04-2019 03:43 AM
Hi
can i configure the 2 Gig ethernet ports on cisco 2851 as part of diffrent vlans and assign ip addresses to that vlans.attahced diagram for the reference.
02-25-2009 11:42 PM
I think the default port in cisco 2851 are routed ports and cannot perform switching. You can directly assign IP address to the two ports and connect them to the switchports in respective VLAN's.
Cheers,
Naveen
02-26-2009 12:18 AM
Hi
Both ports should be in same subnet and should be part of all 4 vlans so if i enable dot1 q on that port i need to create 4 subinterfaces each on both the ports and assign ip addesses..somehow i want to bundle those 2 gig ports.
02-26-2009 01:16 AM
You can use an IRB configuration to have both ports in the same subnet, that is, the same bridge group and configure L3 on the BVI interface.
However, one interface will block due to spanning-tree, and you will find that it's very unlikely that you ever experience faults in the connected switches, so actually there is much true redundancy to gain, at the cost of a more complicated configuration.
02-26-2009 01:30 AM
Hi
so with IRB i will have 4 subinterafces on both gig ports corrosponding to 4 vlands and all 4 subinterfaces will be part of diffrent bridge group on both the gig port.so the configuration will look like
interface Gig 0/0
no ip address
!
interface Gig 0/0.1
encapsulation dot1Q 10
bridge-group 10
!
interface Gig 0/0.2
encapsulation dot1Q 20
bridge-group 20
interface Gig 0/0.3
encapsulation dot1Q 30
bridge-group 30
!
interface Gig 0/0.4
encapsulation dot1Q 40
bridge-group 40
interface Gig 0/1
no ip address
!
interface Gig 0/1.1
encapsulation dot1Q 10
bridge-group 10
!
interface Gig 0/1.2
encapsulation dot1Q 20
bridge-group 20
interface Gig 0/1.3
encapsulation dot1Q 30
bridge-group 30
!
interface Gig 0/1.4
encapsulation dot1Q 40
bridge-group 40
interface BVI 10
ip address 192.168.10.1/24
interface BVI 20
ip address 192.168.20.1/24
interface BVI 10
ip address 192.168.30.1/24
interface BVI 10
ip address 192.168.40.1/24
also it would be great if u can share with me the other solution which u feel complicated.
02-26-2009 01:38 AM
Also configure "bridge irb" and "bridge 10 route ip".
http://www.cisco.com/en/US/tech/tk389/tk815/technologies_tech_note09186a0080094663.shtml
Remember that only one port will be active at all times, so there is no bandwidth to gain.
If you're connecting to a single switch, you can use etherchannel instead, but consider that ISR routers do not have performances enough to fill one gigabit, so in that case too, it is not really worth it.
02-26-2009 02:08 AM
Hi
i am connecting 2 diffrent switches so no chance to configure ether channel.
i dont mind 1 port in blocking mode as its 1 G port.
so in shorft i can have subinterfaces of the main interaface as part of diffrent brigde group.
u were talking about some other complicated configuration in previous mail.u have not highlited the same further.
02-26-2009 03:01 AM
I meant the IRB config that is complicated and in many cases not necessary. If you have L3 switches configure inter-vlan routing there.
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