I would like to draw attention to a general problem with the compatibility of:
Neighbor protocols VS Gigaset VoIP gateways.

Simplified configuration:

WAN/PPPoE <--> MT <==> switch <--> Gigaset

<==>: bonding 2x1Gb eth/802.3ab/mii monitoring/layer2+3/lacp 30s/no 802.1Q

voip gateway:
Gigaset C530IP @ fw:42.263 (422630000000 / V42.00)
switch:
CBS350-8T-E-2G @ fw:3.3.0.16
MT:
hAP ac2 (RBD52G-5HacD2HnD-TC) @ R'OS 6.49.10 Long Term
no 802.1Q/frame tagging

Problem:

In the configuration as above, everything works fine until Neighbor protocols are disabled (CDP/LLDP/MNDP).
After turning them on, the VoiP gateway completely loses connection with LAN within ~30 seconds.
There is no SIP registration to a VoIP server nor TCP/80 to the gateway from WAN.

Problem only concerns the Gigaset gateway.
The remaining equipment behind the switch is available from WAN all the time.

Helps:

- Neighbor disabling
- LACP degradation
- ping MT --> Gigaset every ~20s


Thanks and regards.
Tomek

Thanks for this post!

I suffer from something very similar, but devices are:
Mikrotik hap ac3 LTE
Gigaset A690IP