With below setting I was able to run the test on all 4 devices Message Age = 19 (encoded as 0x13 0x00) Max Age = 20 (encoded as 0x14 0x00) Hello Time = 255 (encoded as 0xFF 0xFF) Forward Delay = 255 (encoded as 0xFF 0xFF)
The results are: Linux bridge: Accepting the new BPDU and accepting all fields as it is given above. Netgear: Not accepting the BPDU, advertising its own with values message age:0, max age: 20, hello time :2 and forward delay 15 Dlink: Not accepting the BPDU , advertising its own with values message age:0, max age: 20, hello time :2 and forward delay 15 Cisco: Not accepting the BPDU, advertising its own with values message age:0, max age: 20, hello time :2 and forward delay 15. In Cisco the configuration is 2950#show spanning-tree summary Root bridge for: VLAN0001. Extended system ID is enabled. PortFast BPDU Guard is disabled EtherChannel misconfiguration guard is enabled UplinkFast is disabled BackboneFast is disabled Default pathcost method used is short Name Blocking Listening Learning Forwarding STP Active ---------------------- -------- --------- -------- ---------- ---------- VLAN0001 0 0 0 2 2 ---------------------- -------- --------- -------- ---------- ---------- 1 vlan 0 0 0 2 2 ====================================== So for the given values except linux all switches are dropping/ignoring the packet. Regards, Sujata --- On Mon, 6/18/12, Vitalii Demianets <[email protected]> wrote: From: Vitalii Demianets <[email protected]> Subject: Re: [Bridge] Query on Sapnning tree implementation from standard point of view To: [email protected] Date: Monday, June 18, 2012, 5:18 PM On Friday 15 June 2012 15:25:39 Sujata Verma wrote: > Thanks. I was doing the same experiment on few switches, i could get hold > of and this is the result: > > Cisco Switch catalyst 2950 : Completely ignoring the packet, so validations > are proper. Hello, Sujata! Would the result of the experiment differ if you set Message Age and Max Age to the correct values while leaving Hello Time and Forward Delay incorrect: Message Age = 19 (encoded as 0x13 0x00) Max Age = 20 (encoded as 0x14 0x00) Hello Time = 255 (encoded as 0xFF 0x00) Forward Delay = 255 (encoded as 0xFF 0x00) How would Cisco switch handle such BPDUs? -- With Best Regards, Vitalii Demianets _______________________________________________ Bridge mailing list [email protected] https://lists.linuxfoundation.org/mailman/listinfo/bridge
