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CML bridging not working

dodgerfan78
Level 1
Level 1

Hey all, I have read several forum posts but cannot get bridge mode on external connections to work. I have done the following:

  • Enabled promiscuous mode and all those other security settings in the VMware port group
  • Added external connection in bridge mode to my lab
  • Connected unmanaged switch to it
  • Connected some network devices to the unmanaged switch (Cat9k g0/0)
  • Enabled DHCP and tried static IP to no avail

NAT mode works but bridge mode does not. Any other ideas to try?

 

 

4 Replies 4

dodgerfan78
Level 1
Level 1

I got this working. I actually created a second NIC but I also disabled Protected Mode within CML as well, so not sure which option worked.

peter-villar
Level 1
Level 1

I had the same problem. System bridge (bridge0) worked fine, but not the new bridge1 I created. The bridge would receive packets (I verified it with tcpdump) from both the physical interface and the bridge-attached lnkxxxxxxxxxxx interface. It would then bridge packets in the direction lnkxxxxxxxxxxx -> physical, but no the other way around.

Configuration in Cockpit:

  • bridge1:
    - ipv4 disabled, ipv6 ignore, mtu auto
    - In terminal, as root:
# ip link set bridge1 type bridge vlan_filtering 1
# echo 16384 > /sys/class/net/bridge1/bridge/group_fwd_mask

(add the group_fwd_mask thing while you're at it, so you get lldp packets).

Configuration in CML:

  • Snooped and protected disabled

Not sure what made it work (I suspect setting vlan_filtering to 1, however bridge0 has it set to 0 and it works).
Then everytime I changed something I would wipe the external connectors, or delete and create them, just in case. Keep trying, it'll work in the end, but everything bridge-related seems a bit messy compared to e.g. gns3.

Hi @peter-villar , Are you running CML in ESXI? Do you use NIC Teaming in ESXI uplinks? If Yes, you also need to set Net.ReversePathFwdCheckPromisc = 1 in ESXI host advanced settings, please refer CML troubleshooting FAQ, Question 7.   https://developer.cisco.com/docs/modeling-labs/faq/#troubleshooting

Hello @rkochery , thanks a lot for your comment. I am not running CML in ESXi, but on bare-metal (a UCS C220 M4).