Multicast Routing and 2811 fa0/1

[jalal_younus]

Hi Guys;

I have a cisco 2811 with:

Cisco IOS Software, 2800 Software (C2800NM-ADVIPSERVICESK9-M), Version 12.4(3d), RELEASE SOFTWARE (fc3)

I have one of its ports (fa0/1) configured as:

interface FastEthernet0/1

no ip address

duplex auto

speed auto

end

and ...

!

interface FastEthernet0/1.101

encapsulation dot1Q 101

ip address 10.26.21.2 255.255.255.0

ip pim query-interval 1

ip pim sparse-dense-mode

ip igmp version 3

end

This port is connected to a laptop, on a gigabit ethernet port. That lap top port is configuured as

10.26.21.3 255.255.255.0

with default gateway as:

10.26.21.2 255.255.255.0

The reason for doing that is that the laptop is a multicast source. My trouble is that this interface (fa0/1 and hence fa0/1.101) on  2811 is coming up. It is in up down state.

Can somebody tell me what should i do?  if i just use fa0/1 and not create a sub interface,  it still does not work/come up.

reagdrs

[Nagendra Kumar Nainar]

Hi,

Am I asuming right that the line protocol is down?. If so, it is not related to L3 configuration or multicats being enabled. I would check the speed/duplex settings.

What is your laptop speed?. Is it 100 Mbps (fastethernet) or 1 Gbps (gigabitethernet0?. If the laptop is defaulting to Gbps, can you try setting to 100 Mbps?. Also try setting the duplex as full on the route rside and see if it helps.

HTH,

Nagendra

[Reza Sharifi · Accepted solution]

Hi,

On the router, you have configured the router with dot1Q.  The PC doesn't understand dot1Q.

encapsulation dot1Q 101

Delete the sub-interface and change your config to this and try again:

interface FastEthernet0/1

ip address 10.26.21.2 255.255.255.0

duplex auto

speed auto

end

HTH

[jalal_younus]

thanks alot guys,  its working.

[Reza Sharifi]

what was the issue?

[jalal_younus]

removed encapsulation from the sub interfcae and the subinterface itself.

thanks,

[Reza Sharifi]

Can you please rate the post and mark it as answered, so others can benefit from it?

Thanks,

[jalal_younus]

sure thanks.