Cisco Support Community
cancel
Showing results for 
Search instead for 
Did you mean: 
cancel
Community Member

2801 Bridging

Hello -

I've just inherited a design that I think has an inappropriate device

specified. Since I can't find a definitive answer on-line, I thought I'd present it here:

Does the Cisco 2801 router do bridging any more powerfully than bridging done on most routers, i.e. bridging IRB, with only one BVI interface per bridge group, and no ?trunking? capabilities? In other words, on the 2801 (an ?integrated services? router) can one configure a VLAN SVI and layer 2 trunk, with which it might be able to function at L2 with a Catalyst L2/L3 switch?

Many thanks for any answers you can provide.

2 ACCEPTED SOLUTIONS

Accepted Solutions
Hall of Fame Super Gold

Re: 2801 Bridging

Richard

I do not think it is necessarily an inappropriate device. The 2801 has two FastEthernet ports which are capable of trunking and performing inter-vlan routing (router on a stick). Also the 2801 has these interface card slots: 4 slots; 2 slots support HWIC, WIC, VIC, or VWIC type modules

And the HWICs include these:

Ethernet Switching HWICs

HWIC-4ESW 4-port single-wide 10/100BaseT Ethernet switch HWIC

HWIC-D-9ESW 9-port double-wide 10/100BaseT Ethernet switch HWIC

HWIC-4ESW-POE 4-port Ethernet switch HWIC, Power over Ethernet capable

HWIC-D-9-ESW-POE 9-port Ethernet switch HWIC, Power over Ethernet capable

That information comes from the 2801 data sheet at this link:

http://www.cisco.com/en/US/products/ps5854/products_data_sheet0900aecd8016fa68.html

So I think it looks like it might well have the capability to fit into the design and provide switching capability.

HTH

Rick

Hall of Fame Super Gold

Re: 2801 Bridging

Richard

Without knowing anything about the design (topology, functionality, requirements, etc) I am not in much position to say whether to forego bridging altogether. But given the capabilities of the 2801 it does seem that there are good alternatives.

To answer your specific questions:

a) I am not aware of any limit on how many subinterfaces can be created (other than things like limits imposed by IDBs).

b) I do not believe that router on a stick has any interaction with STP. The router does not generate or process BPDUs so I do not see how it would make any difference.

HTH

Rick

5 REPLIES
Hall of Fame Super Gold

Re: 2801 Bridging

Richard

I do not think it is necessarily an inappropriate device. The 2801 has two FastEthernet ports which are capable of trunking and performing inter-vlan routing (router on a stick). Also the 2801 has these interface card slots: 4 slots; 2 slots support HWIC, WIC, VIC, or VWIC type modules

And the HWICs include these:

Ethernet Switching HWICs

HWIC-4ESW 4-port single-wide 10/100BaseT Ethernet switch HWIC

HWIC-D-9ESW 9-port double-wide 10/100BaseT Ethernet switch HWIC

HWIC-4ESW-POE 4-port Ethernet switch HWIC, Power over Ethernet capable

HWIC-D-9-ESW-POE 9-port Ethernet switch HWIC, Power over Ethernet capable

That information comes from the 2801 data sheet at this link:

http://www.cisco.com/en/US/products/ps5854/products_data_sheet0900aecd8016fa68.html

So I think it looks like it might well have the capability to fit into the design and provide switching capability.

HTH

Rick

Community Member

Re: 2801 Bridging

Rick,

Thank you very much for the reply. So the answer is to forego the bridging idea altogether. I had forgotten how things were done before MLSs (and before my time too). If I may ask, with router-on-a-stick,

a) Is there a limit to how many subinterfaces can be created on an interface?

b) Is STP affected at all? Specifically, can I still use PVST (I would think so), or must I revert to 802.1D?

Thanks again.

Hall of Fame Super Gold

Re: 2801 Bridging

Richard

Without knowing anything about the design (topology, functionality, requirements, etc) I am not in much position to say whether to forego bridging altogether. But given the capabilities of the 2801 it does seem that there are good alternatives.

To answer your specific questions:

a) I am not aware of any limit on how many subinterfaces can be created (other than things like limits imposed by IDBs).

b) I do not believe that router on a stick has any interaction with STP. The router does not generate or process BPDUs so I do not see how it would make any difference.

HTH

Rick

Community Member

Re: 2801 Bridging

Answers I was hoping for -- thanks again for your help.

Re: 2801 Bridging

you can come to know how many subinterfaces you can create like this..

#interface serial 0.?

"?" type it first and then press enter you will get very large number of many digits... so that number represent the number of subinterfaces you can create on the perticular physical interface...

regards

Devang

154
Views
0
Helpful
5
Replies
CreatePlease to create content