Hello, Two years ago there was a post regarding a patch to the Linux kernel allowing it to bridge of two VLANs with Cisco's PVST+ (https://lists.linux-foundation.org/pipermail/bridge/2006-May/004921.html). I tried contacting both Gergely Madarasz (the author of the patch) and Ian Schwimmer (who started the thread) without any luck. Does anyone has this patch? Or, for that matter, a solution on how to do this? I'm currently using ebtables on SLES10SP2 to DROP the switch's BPDUs, avoiding it from shutting down the port; I have also changed the bridge's ULA in order to use "per-vlan" STP. This situation if far from ideal, of course: it would be great to have STP working between the Linux box and the Cisco switch (or any other switch), allowing it [the Linux Box] to "fail-to-wire" if something was to go wrong. Thank you, JP
JP; I've had this very issue. I know that 2.6.24-16 allows PVST BPDUs to cross the bridge. Linux won't speak Cisco PVST+ but it will pass the BPDU's so that Cisco devices on both sides can communicate about the link state. That has been my experience anyway (long and painful I might add). G -----Original Message----- From: bridge-bounces at lists.linux-foundation.org [mailto:bridge-bounces at lists.linux-foundation.org] On Behalf Of Jo?o Pedro Sent: 25 November 2008 3:31 PM To: bridge at lists.linux-foundation.org Subject: [Bridge] Bridging VLANs and PVST+ Hello, Two years ago there was a post regarding a patch to the Linux kernel allowing it to bridge of two VLANs with Cisco's PVST+ (https://lists.linux-foundation.org/pipermail/bridge/2006-May/004921.html). I tried contacting both Gergely Madarasz (the author of the patch) and Ian Schwimmer (who started the thread) without any luck. Does anyone has this patch? Or, for that matter, a solution on how to do this? I'm currently using ebtables on SLES10SP2 to DROP the switch's BPDUs, avoiding it from shutting down the port; I have also changed the bridge's ULA in order to use "per-vlan" STP. This situation if far from ideal, of course: it would be great to have STP working between the Linux box and the Cisco switch (or any other switch), allowing it [the Linux Box] to "fail-to-wire" if something was to go wrong. Thank you, JP _______________________________________________ Bridge mailing list Bridge at lists.linux-foundation.org https://lists.linux-foundation.org/mailman/listinfo/bridge
Hi JP; I understand more clearly now - thank you for the example. In the use case that I struggled against I needed the BPDU's to traverse the bridge as we were counting on the Cisco switches to force a blocking state on a redundant link. I have seen the case you are describing and assumed that I would have to live with it as the Linux bridge was "doing the right thing". PVST is a proprietary Cisco protocol. I guess wouldn't expect an open source project to "re-write" the VLAN header for a proprietary protocol. Anyone else have any thoughts on this? G -----Original Message----- From: Joao Pedro [mailto:countzero at sapo.pt] Sent: 25 November 2008 5:10 PM To: Geoff Wiener Subject: RE: [Bridge] Bridging VLANs and PVST+ Hi Geoff, thank you for your answer. Geoff Wiener <gwiener at aenigmacorp.com> wrote:> I've had this very issue. I know that 2.6.24-16 allows PVST BPDUs > to cross the bridge. Linux won't speak Cisco PVST+ but it will pass > the BPDU's so that Cisco devices on both sides can communicate about > the link state. >But isn't that part of the problem? Imagine this situation, I have: 1 physical interface - eth0; 2 virtual lan interfaces - vlan15 and vlan16. 1 bridge - br0 - bridging vlan15 and vlan16. The reason I have to filter the PVST+ BPDUs out (with ebtables) is that, when the Cisco switch sees a BDPU on VLAN 15 that belonged originally to VLAN 16, it will assume a loop was detected and shut down the switch port where eth0 is connected. If Linux could convert the VLAN 15 BDPU to a VLAN 16 BDPU, before sending it to VLAN 16, I believe the problem would be solved. Regards, JP