Rutger, Cisco s2witches allow you tyo specify which VLANS will be allowed to traverse a trunk link. Your first example simply identifies the port as a trunk link without any limitations as to which VLANs can use it. Your second example sets up the port as a trunk link but limits the traffic to VLAN 204. This just gives you a little more control over the paths that your traaffic takes.
You can think of it as kind of an access-list for the trunk. HTH, Karen *********** REPLY SEPARATOR *********** On 2/24/2003 at 9:22 PM Rutger Blom wrote: >Hello, > >I'm not a Cisco expert and Ionly have some field experience with >configuring >switches. So please forgive me for my questions. > >Today I've been busy configuring a trunk on some Cisco 2950c/2924c >switches. >Could somebody explain the difference between these two configurations: > >Config 1: >interface FastEthernet0/25 > switchport mode trunk > no ip address > >Config 2: >interface FastEthernet0/25 > switchport access vlan 204 > switchport mode trunk > no ip address > >With the first configuration, clients on the VLAN 204 did not get an IP >address from the DHCP server. Even clients with a static IP-address could >not establish IP contact with other hosts. The switch however could see >other switches via the "show cdp" commando. It could also "ping" other >switches. (all switches are in a separate management VLAN). >When I made the change resulting in configuration two everything worked >fine. >Note that the trunk is a FX link to a Cisco 2924c switch. This switch has >two FX ports. Both ports are configured to be trunk ports. I configured one >of those FX ports with the "switchport access vlan 204" aswell. The other >FX >trunk port has a configuration as shown in config 1. This trunk port has a >FX link to a third Cisco 2924c switch. This switch operates in VLAN 107. >Everything works fine in this switch. I did not have to specify the >"switchport access vlan 107" on either of these ports. > >Is there some incompatibility issue between 2950c and 2924c? Why didn't it >work with config 1 on the Cisco 2950c switch? Can a Cisco 2924c switch have >its two FX ports configured as a trunk like in config 1? Even when those >two >FX ports have physical links to different switches? > >A lot of questions, but I'm just very curious. >To make this a bit more clear I've attached a .txt file with a simple >drawing and configurations of the current situation. > >Thanks in advance, > >Rutger >Sweden > > > > >[demime removed a uuencoded section named site.txt which was 30 lines] Message Posted at: http://www.groupstudy.com/form/read.php?f=7&i=63675&t=63653 -------------------------------------------------- FAQ, list archives, and subscription info: http://www.groupstudy.com/list/cisco.html Report misconduct and Nondisclosure violations to [EMAIL PROTECTED]
