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New Member

Setting up a Span session for an Etherchannel

Does anyone know of a Cisco web page, I haven't found one, which explains how traffic on a CatOS switch is transferred from a 4 port etherchannel to a single span port. For example, I need to know how a single 100Mb\s Full duplex port handles traffic from four 100Mb\s Full duplex ports. I am querying this as I need to be able to estimate real-time data transfer rates over an etherchannel.

1 ACCEPTED SOLUTION

Accepted Solutions
Bronze

Re: Setting up a Span session for an Etherchannel

Cant tell if you are after span info or port statistics, so here's both.

When you span an etherchannel port to another port it will show you that it spanned all of the ports in the channel. If the aggregate of those ports is too much for the span port packets will be dropped. See below when I span 4/10 it responds that the source is 4/10,8/11.

CAT2> (enable) sh port chann

Port Status Channel Admin Ch

Mode Group Id

----- ---------- -------------------- ----- -----

4/9 connected on 249 769

4/11 connected on 249 769

----- ---------- -------------------- ----- -----

4/1 connected on 137 865

4/2 notconnect on 137 865

5/1 connected on 137 865

5/2 notconnect on 137 865

----- ---------- -------------------- ----- -----

4/10 connected on 248 869

8/11 connected on 248 869

----- ---------- -------------------- ----- -----

4/12 connected on 247 870

8/10 connected on 247 870

----- ---------- -------------------- ----- -----

Port Device-ID Port-ID Platform

----- ------------------------------- ------------------------- ----------------

4/9

4/11

----- ------------------------------- ------------------------- ----------------

4/1 SCA04020134(CAT1) 4/16 WS-C6509

4/2

5/1 SCA04020134(CAT1) 6/16 WS-C6509

5/2

----- ------------------------------- ------------------------- ----------------

4/10

8/11

----- ------------------------------- ------------------------- ----------------

4/12

8/10

----- ------------------------------- ------------------------- ----------------

CAT2> (enable) set span 4/10 9/48

2003 Jul 28 08:12:52 CST -06:00 %SYS-5-SPAN_CFGSTATECHG:local span session inact

ive for destination port 9/48

Destination : Port 9/48

Admin Source : Port 4/10

Oper Source : Port 4/10,8/11

Direction : transmit/receive

Incoming Packets: disabled

Learning : enabled

Multicast : enabled

Filter : -

Status : active

These next commands show counters on the port.

CAT2> (enable) sh port count 9/48

Port Align-Err FCS-Err Xmit-Err Rcv-Err UnderSize

----- ---------- ---------- ---------- ---------- ---------

9/48 6 0 0 0 0

Port Single-Col Multi-Coll Late-Coll Excess-Col Carri-Sen Runts Giants

----- ---------- ---------- ---------- ---------- --------- --------- ---------

9/48 70797 5635 2 13 0 6 0

Last-Time-Cleared

CAT2> (enable) sh port mac 9/48

Port Rcv-Unicast Rcv-Multicast Rcv-Broadcast

-------- -------------------- -------------------- --------------------

9/48 0 0 280797

Port Xmit-Unicast Xmit-Multicast Xmit-Broadcast

-------- -------------------- -------------------- --------------------

9/48 39602686381 150896080 56869577

Port Rcv-Octet Xmit-Octet

-------- -------------------- --------------------

9/48 38871910 16512185621934

MAC Dely-Exced MTU-Exced In-Discard Out-Discard

-------- ---------- ---------- ---------- -----------

9/48 0 0 20 1845957779

4 REPLIES
Cisco Employee

Re: Setting up a Span session for an Etherchannel

If the destination SPAN port is congested, packets are dropped in the output queue.

New Member

Re: Setting up a Span session for an Etherchannel

The 6500 in question is not IOS based i.e. the command set is the older " set vlan" type. I can use "show port" or "show port counters". This gives me statistics for collisions, runts, giants, alignment errors, FCS's,and also transmit & receive errors.

I know that switches which use the standard IOS arrangement which has interfaces as opposed to ports can yield statistics on output queues but how can I get these stats here?

Apologies if the switch type \ OS was unclear.

Bronze

Re: Setting up a Span session for an Etherchannel

Cant tell if you are after span info or port statistics, so here's both.

When you span an etherchannel port to another port it will show you that it spanned all of the ports in the channel. If the aggregate of those ports is too much for the span port packets will be dropped. See below when I span 4/10 it responds that the source is 4/10,8/11.

CAT2> (enable) sh port chann

Port Status Channel Admin Ch

Mode Group Id

----- ---------- -------------------- ----- -----

4/9 connected on 249 769

4/11 connected on 249 769

----- ---------- -------------------- ----- -----

4/1 connected on 137 865

4/2 notconnect on 137 865

5/1 connected on 137 865

5/2 notconnect on 137 865

----- ---------- -------------------- ----- -----

4/10 connected on 248 869

8/11 connected on 248 869

----- ---------- -------------------- ----- -----

4/12 connected on 247 870

8/10 connected on 247 870

----- ---------- -------------------- ----- -----

Port Device-ID Port-ID Platform

----- ------------------------------- ------------------------- ----------------

4/9

4/11

----- ------------------------------- ------------------------- ----------------

4/1 SCA04020134(CAT1) 4/16 WS-C6509

4/2

5/1 SCA04020134(CAT1) 6/16 WS-C6509

5/2

----- ------------------------------- ------------------------- ----------------

4/10

8/11

----- ------------------------------- ------------------------- ----------------

4/12

8/10

----- ------------------------------- ------------------------- ----------------

CAT2> (enable) set span 4/10 9/48

2003 Jul 28 08:12:52 CST -06:00 %SYS-5-SPAN_CFGSTATECHG:local span session inact

ive for destination port 9/48

Destination : Port 9/48

Admin Source : Port 4/10

Oper Source : Port 4/10,8/11

Direction : transmit/receive

Incoming Packets: disabled

Learning : enabled

Multicast : enabled

Filter : -

Status : active

These next commands show counters on the port.

CAT2> (enable) sh port count 9/48

Port Align-Err FCS-Err Xmit-Err Rcv-Err UnderSize

----- ---------- ---------- ---------- ---------- ---------

9/48 6 0 0 0 0

Port Single-Col Multi-Coll Late-Coll Excess-Col Carri-Sen Runts Giants

----- ---------- ---------- ---------- ---------- --------- --------- ---------

9/48 70797 5635 2 13 0 6 0

Last-Time-Cleared

CAT2> (enable) sh port mac 9/48

Port Rcv-Unicast Rcv-Multicast Rcv-Broadcast

-------- -------------------- -------------------- --------------------

9/48 0 0 280797

Port Xmit-Unicast Xmit-Multicast Xmit-Broadcast

-------- -------------------- -------------------- --------------------

9/48 39602686381 150896080 56869577

Port Rcv-Octet Xmit-Octet

-------- -------------------- --------------------

9/48 38871910 16512185621934

MAC Dely-Exced MTU-Exced In-Discard Out-Discard

-------- ---------- ---------- ---------- -----------

9/48 0 0 20 1845957779

New Member

Re: Setting up a Span session for an Etherchannel

Thanks, the show port mac probably indicates the packets discarded through not being capable of being transmitted. This should give me an idea of how many packets are lost by trying to pass a potential 4 X 100Mb\s of data down a single 100 Mb\s port.

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