Also, and importantly: While ISL tags *all* frames with VLAN info, 802.1Q does *not*: Traffic on the "native" VLAN is forwarded unaltered. So, an 802.1Q trunk will not work at all if the native VLANs are not identical, whereas an ISL trunk can if nothing goes wrong. -Gabriel McCall, CCDP/CCNP+Sec <[EMAIL PROTECTED]> wrote in message [EMAIL PROTECTED]">news:[EMAIL PROTECTED]... > > Benny, > > Try thinking of trunking as a "service" that runs on the access links, > multiplexing traffic from multiple vlans. Those links have a native VLAN > that they revert to if trunking breaks down. For example, if you reboot a > switch and it's unable to negotiate the trunking due to a mismatch in the > negotiation type then the ports would only pass traffic for it's native > VLAN. I had this happen on a couple of switches on my network shortly after > I took over but before the new network design was deployed. It turned out > that one end of the link was configured as "desirable" and the other end > was configured as "on". The "on" end had been changed from "desirable" to > "on" sometime in the past and the trunk link just kept going because it > hadn't had to be renegotiated. When the switch was rebooted, the > "desirable" end was expecting negotiation and when it didn't get it, it > didn't set up the trunking. > > If the ports on either end of the link aren't assigned a vlan then the > native vlan is vlan 1 by default. Its generally a good idea to make sure > that the native vlan of the trunking ports is the same as your management > vlan so that you can still get to switch if trunking goes down. > > Karen E Young > ELF Technologies, Inc > [EMAIL PROTECTED] > > > > >> What is native vlan in the context of IEEE 802.1Q trunk restriction ? **NOTE: New CCNA/CCDA List has been formed. For more information go to http://www.groupstudy.com/list/Associates.html _________________________________ UPDATED Posting Guidelines: http://www.groupstudy.com/list/guide.html FAQ, list archives, and subscription info: http://www.groupstudy.com Report misconduct and Nondisclosure violations to [EMAIL PROTECTED]
