Hi everyone,
I've met an issue on my switch that I can't explain.
Indeed, I've a fairly simple installation:
- DATA Router (Livebox V5)
- VOIP Router
- Switch SG350-52P
I've therefore implemented the following configuration:
- VLAN 1 = DATA
- VLAN 2 = VOICE
- Port Gi49 = ACCESS VLAN 2
- Port Gi50 = ACCESS VLAN 1
- All other ports are in TRUNK ALLOWED VLAN ADD 1-2 (NATIVE VLAN 1)
The problem is, when the VOICE router is plugged in, whether on the Gi49 or Gi50 port, nothing to report, everything is acting normally.
But as soon as the DATA router (Livebox) is plugged in, wether on the DATA or VOICE port, the switch constantly reboot, about 30s after having booted well.
The test is not reproduced with a router other than the Livebox in the same configuration (one routeur for DATA, another for VOICE), so I imagine that the source is on it.
On the switch, we see that the reboot seems to be linked to a flood of DHCPv6 messages coming from the Livebox:
switch#10-Jun-2022 15:07:18 %LINK-I-Up: gi50
10-Jun-2022 15:07:18 %LINK-I-Up: Vlan 1
10-Jun-2022 15:07:18 %STP-W-PORTSTATUS: gi24: STP status Forwarding
10-Jun-2022 15:07:21 %DHCPV6CLIENT-I-STATELESSDATA: DHCP Stateless information received on vlan 1 from DHCP Server ffff::abcd:1234:a1b2:c3d4 was updated
10-Jun-2022 15:07:33 %DHCPV6CLIENT-I-ADDR: DHCPv6 Address :: received on vlan 1 from DHCP Server ffff::abcd:1234:a1b2:c3d4 was added
10-Jun-2022 15:07:34 %DHCPV6CLIENT-I-ADDR: DHCPv6 Address :: received on vlan 1 from DHCP Server ffff::abcd:1234:a1b2:c3d4 was validated
10-Jun-2022 15:07:34 %DHCPV6CLIENT-I-ADDR: DHCPv6 Address :: received on vlan 1 from DHCP Server ffff::abcd:1234:a1b2:c3d4 was renewed
10-Jun-2022 15:07:34 %DHCPV6CLIENT-I-ADDR: DHCPv6 Address :: received on vlan 1 from DHCP Server ffff::abcd:1234:a1b2:c3d4 was renewed
10-Jun-2022 15:07:34 %DHCPV6CLIENT-I-ADDR: DHCPv6 Address :: received on vlan 1 from DHCP Server ffff::abcd:1234:a1b2:c3d4 was renewed
...
10-Jun-2022 15:07:53 %DHCPV6CLIENT-I-ADDR: DHCPv6 Address :: received on vlan 1 from DHCP Server ffff::abcd:1234:a1b2:c3d4 was renewed
10-Jun-2022 15:07:53 %DHCPV6CLIENT-I-ADDR: DHCPv6 Address :: received on vlan 1 from DHCP Server ffff::abcd:1234:a1b2:c3d4 was renewed
10-Jun-2022 15:07:53 %DHCPV6CLIENT-I-ADDR: DHCPv6 Address :: received on vlan 1 from DHCP Server ffff::abcd:1234:a1b2:c3d4 was renewed
The defect seems well isolated from the Livebox : by deactivating IPv6 on it, the issue disappears on the switch side.
Does any of you have an idea where the problem could come from, if it's an isolated case on the Livebox (maybe THIS Livebox in particular, maybe a defect), and how to get around the problem on the switch without disabling IPv6 on the Livebox?
Thank you and regards
Tom
