Getting around switchport host because of IP Phones in use. 2

[gavinkluska]

http://www.tek-tips.com/viewthread.cfm?qid=908647&page=4

read this article. I am having this problem. BUT I have to maintain the port on the 2950 with switchport mode trunk for the VOIP to work with MITEL IP Phones!

Are there any settings on the Intel Pro 1000 MT cards which will fix the problem? I am also seeing the issue with Broadcom Netextreme cards in New HP/Compaq desktops although not as serious as the IBM thinkpads with an Intel Pro 1000 MT nic.

Any help welcome and thank in advance.
Gavin Kluska

 

[ADB100]

You do not need to configure a trunk on the newer switches, you can set the port as an access port and add a voice VLAN. This makes the port work like a psuedo trunk where there are only 2 VLAN's - the Native VLAN (untagged) and a single Tagged VLAN (Voice VLAN). With the older (3500/2900XL) switches you had to configure the ports as trunks but with the newer ones (2950, 3550, 3750 etc) you can use the Voice VLAN feature.

I have deployed Mitel IP Phones using this configuration:

interface FastEthernet0/1
switchport access vlan 20
switchport mode access
switchport voice vlan 500
switchport port-security maximum 3
mls qos trust cos
spanning-tree portfast

Make sure you have the QoS configured correctly as well to support the expedite queue and map CoS 5 into this queue (4). You will need a new release to support the expedite queue (12.1(12c)EA1 or above, although since the software is free I would just put the latest on).

wrr-queue bandwidth 10 20 70 0
wrr-queue cos-map 1 0 1
wrr-queue cos-map 2 2 4
wrr-queue cos-map 3 3 6 7
wrr-queue cos-map 4 5

Good luck

Andy

 

[gavinkluska]

thanks for the update ADB100. Your fix works however we want maintain our network such that uplinks do not have to be managed. I have found that although "spanning-tree portfast" will not work unless trunk mode is turned off you can use "spanning-tree portfast trunk" which will allow a flexible network structure and will continue to cope with spanning tree. see

http://www.cisco.com/en/US/products..._guide_chapter09186a008007e6bd.html#wp1042489

for more info.

Thanks again
Gavin Kluska

 

[ADB100]

Gavin

I am slightly confused by your 2 comments:

'...we want maintain our network such that uplinks do not have to be managed.'

'...you can use "spanning-tree portfast trunk" which will allow a flexible network structure and will continue to cope with spanning tree...'

What I suggested was for access-ports where you connect a phone and piggy-back a PC off the phone; this is what Voice VLAN's are for. For uplinks between the access and distribution layers (core layers as well but not usually in a normal campus design) you would make these trunks and trunk the relevent VLAN's that are needed on the Access Switch - usually a Voice VLAN and a Data VLAN.

Cisco's recommendations are to try to reduce the number of STP instances and keep the diameter of each one to a minimum. I would take a trip on over to CCO and have a look at the Campus Design Guides. These detail the building-blocks that Cisco have been pushing since 1999 so they are tried and tested.

Andy

 

[gavinkluska]

Agreed, things are a bit confusing. We run a small network which is very disparate with a small number of staff to maintain. The trade-offs are between using inexperienced staff to maintain the network as well as keeping the cost low and flexibility in an environment which gets changed at the drop of a hat. Demountable project huts etc which spring up like mushrooms and disappear just as quick. Yeah it is not a great design but it works OK and we all manage to cope with the change and not break it.

Gavin Kluska