Re: Vlans and trunking [7:18442]
Thanks for the comments, what they're doing is assigning a small number of vlans 2 to 3 on the switches and linking them, so no problems with VLAN 1 but obviously this approach doesn't scale cheers Pat ""Patrick Donlon"" wrote in message [EMAIL PROTECTED]">news:[EMAIL PROTECTED]... > I'm familiar with the concept off using vlan trunks to send vlan information > to a connected switch, however I've been working on a new site and have > discovered that they use a different approach. I was surprised to find that > they just plug in the port off one switch straight into the next switch with > a crossover and off they go. > This works but could someone point out the pitfalls off such an approach > > cheers > > Pat Message Posted at: http://www.groupstudy.com/form/read.php?f=7&i=18570&t=18442 -- FAQ, list archives, and subscription info: http://www.groupstudy.com/list/cisco.html Report misconduct and Nondisclosure violations to [EMAIL PROTECTED]
Re: Vlans and trunking [7:18442]
You can too do etherchannel with a single VLAN though it's not as common. Dave Ken Mays wrote: > > Another problem with this approach is that you can't do Fast EtherChannel > between the switches if you're not using trunks. Also, this will inhibit > VLAN propagation. > > It's better all around to use the correct Cisco technique for trunking > switches. -- David Madland Sr. Network Engineer CCIE# 2016 Qwest Communications Int. Inc. [EMAIL PROTECTED] 612-664-3367 "Emotion should reflect reason not guide it" Message Posted at: http://www.groupstudy.com/form/read.php?f=7&i=18506&t=18442 -- FAQ, list archives, and subscription info: http://www.groupstudy.com/list/cisco.html Report misconduct and Nondisclosure violations to [EMAIL PROTECTED]
Re: Vlans and trunking [7:18442]
Why's this? I've configured FastEtherChannel without having to make the FEC a trunk but this was between a 5500 and a 7500.. have you more information for me to read indicating that you MUST make a FEC link a trunk to work properly between switches? As an aside: You don't always have to use trunking between switches to share VLANs especially if you have only a few VLANs (2 or 3) i.e. you have a 2900 switch with 1/2 it's ports in VLAN 1 and 1/2 of them in VLAN2, you could then connect that 2900 to another switch by simply connecting a cable, one to a port for each VLAN 1 and VLAN2, and connect to the other switch (be sure to setup the proper VLAN on the "destination" switch). This not only allows the switches to "share" VLANs as they would with a trunk but you've now gotten 400Mbps (200 on each link) between the switches for the info to travel over instead of the 200 you would have over a single FastEthernet trunk. Mike W. "Ken Mays" wrote in message [EMAIL PROTECTED]">news:[EMAIL PROTECTED]... > Another problem with this approach is that you can't do Fast EtherChannel > between the switches if you're not using trunks. Also, this will inhibit > VLAN propagation. > > It's better all around to use the correct Cisco technique for trunking > switches. Message Posted at: http://www.groupstudy.com/form/read.php?f=7&i=18505&t=18442 -- FAQ, list archives, and subscription info: http://www.groupstudy.com/list/cisco.html Report misconduct and Nondisclosure violations to [EMAIL PROTECTED]
Re: Vlans and trunking [7:18442]
Then they're only x-mitting the traffic for one VLAN.. (which ever VLAN the port is in on the one switch)... If they're only using VLAN 1 (default for all ports) then you can use this method because trunks are only needed for multiple VLANs. Mike W. "Patrick Donlon" wrote in message [EMAIL PROTECTED]">news:[EMAIL PROTECTED]... > I'm familiar with the concept off using vlan trunks to send vlan information > to a connected switch, however I've been working on a new site and have > discovered that they use a different approach. I was surprised to find that > they just plug in the port off one switch straight into the next switch with > a crossover and off they go. > This works but could someone point out the pitfalls off such an approach > > cheers > > Pat Message Posted at: http://www.groupstudy.com/form/read.php?f=7&i=18501&t=18442 -- FAQ, list archives, and subscription info: http://www.groupstudy.com/list/cisco.html Report misconduct and Nondisclosure violations to [EMAIL PROTECTED]
RE: Vlans and trunking [7:18442]
Another problem with this approach is that you can't do Fast EtherChannel between the switches if you're not using trunks. Also, this will inhibit VLAN propagation. It's better all around to use the correct Cisco technique for trunking switches. Message Posted at: http://www.groupstudy.com/form/read.php?f=7&i=18488&t=18442 -- FAQ, list archives, and subscription info: http://www.groupstudy.com/list/cisco.html Report misconduct and Nondisclosure violations to [EMAIL PROTECTED]
Re: Vlans and trunking [7:18442]
Kell is right about things being a mess later on. The default vlan is VLAN 1, which carries the protocol control traffic for a switched network. Things like STP BPDU's, DTP (ISL and dot1q), VTP, PAgP, etc... In addition, if the management interfaces are set to VLAN 1 (the default), then administrative traffic like SNMP and telnet will use it too. Keep in mind that VLAN 1 goes to ALL switches regardless of trunking and VLAN paring settings. You coiuld set up trunking so that every vlan EXCEPT VLAN 1 gets trunked and you'll still get VLAN 1 trunked. Nature of the beast. You can pare it out in the config, but the switch will still do it behind your back. Because of this,its a good idea not to have users on VLAN 1 in any network. As an example, if there's a broadcast storm it can take down the network by preventing the protocol traffic from reaching its destination before the timeouts or you could be locked out of the network unless you use a console port. Overall, its a little better than a hub network due to the differences in collision domain structure, but you still have the issue with the broadcast domain. I found that it tends to be a royal pain in the neck when theres a problem. Even if all you do is set it up so that everyone is on the same vlan, as long as its something besides VLAN 1 your network will be a little more manageable. HTH, Karen *** REPLY SEPARATOR *** On 9/4/2001 at 12:33 PM Patrick Donlon wrote: >I'm familiar with the concept off using vlan trunks to send vlan information >to a connected switch, however I've been working on a new site and have >discovered that they use a different approach. I was surprised to find that >they just plug in the port off one switch straight into the next switch with >a crossover and off they go. >This works but could someone point out the pitfalls off such an approach > >cheers > >Pat Message Posted at: http://www.groupstudy.com/form/read.php?f=7&i=18469&t=18442 -- FAQ, list archives, and subscription info: http://www.groupstudy.com/list/cisco.html Report misconduct and Nondisclosure violations to [EMAIL PROTECTED]
RE: Vlans and trunking [7:18442]
Yes with this approach they are running everything on the default vlan, and things will get messy later on. For small networks you can get away with this, but you lose all the advantages of carving up your broadcast domains with VLANs. Kell -Original Message- From: Patrick Donlon [mailto:[EMAIL PROTECTED]] Sent: Tuesday, September 04, 2001 9:34 AM To: [EMAIL PROTECTED] Subject: Vlans and trunking [7:18442] I'm familiar with the concept off using vlan trunks to send vlan information to a connected switch, however I've been working on a new site and have discovered that they use a different approach. I was surprised to find that they just plug in the port off one switch straight into the next switch with a crossover and off they go. This works but could someone point out the pitfalls off such an approach cheers Pat Message Posted at: http://www.groupstudy.com/form/read.php?f=7&i=18450&t=18442 -- FAQ, list archives, and subscription info: http://www.groupstudy.com/list/cisco.html Report misconduct and Nondisclosure violations to [EMAIL PROTECTED]
