I have a MBIM LTE modem with 2 network interfaces (one is a VLAN) and I am trying to configure both connections, given that IPs, Gateways, etc. are obtained through MBIM protocol, so the routing is to be done manually.Googling a lot and searching in this forum, the solution seemd to be this one, namely using a second and third routing table and routing rules.This solution is usually suggested for eth network devices, but I assume there should be no difference, however I can not get to make both networks to work together and in the best case I can ping from the 1st interface only, while the vlan does not ping at all.My configuration is the following:Let's say the MBIM protocol gives the following data for the two connectionsSession 1IP=10.39.187.213/24GW=10.39.187.1Session 2IP=5.91.204.208/24GW=5.91.204.1This is the routingip link add link wwp0s20u1u1u4 name wwp0s20u1u1u4.0 type vlan id 0ip set link wwp0s20u1u1u4 upip route show table maindefault    nexthop via 10.39.187.1  dev wwp0s20u1u1u4 weight 1    nexthop via 5.91.204.1  dev wwp0s20u1u1u4.0 weight 15.91.204.0/24 dev wwp0s20u1u1u4.0  proto kernel  scope link  src 5.91.204.20810.39.187.0/24 dev wwp0s20u1u1u4  proto kernel  scope link  src 10.39.187.213ip route show table seconddefault via 10.39.187.1 dev wwp0s20u1u1u410.39.187.0/24 dev wwp0s20u1u1u4  scope link  src 10.39.187.213ip route show table thirddefault via 5.91.204.1 dev wwp0s20u1u1u4.05.91.204.0/24 dev wwp0s20u1u1u4.0  scope link  src 5.91.204.208ip rule0:  from all lookup local32762:  from all to 5.91.204.0/24 lookup third32763:  from 5.91.204.0/24 lookup third32764:  from all to 10.39.187.0/24 lookup second32765:  from 10.39.187.0/24 lookup second32766:  from all lookup main32767:  from all lookup defaultThis is the result of the pingsping -I wwp0s20u1u1u4 8.8.8.8 -c 4PING 8.8.8.8 (8.8.8.8) from 10.39.187.213 wwp0s20u1u1u4: 56(84) bytes of data.64 bytes from 8.8.8.8: icmp_seq=1 ttl=42 time=121 ms64 bytes from 8.8.8.8: icmp_seq=2 ttl=42 time=79.4 ms64 bytes from 8.8.8.8: icmp_seq=3 ttl=42 time=111 ms64 bytes from 8.8.8.8: icmp_seq=4 ttl=42 time=110 ms--- 8.8.8.8 ping statistics ---4 packets transmitted, 4 received, 0% packet loss, time 3002msrtt min/avg/max/mdev = 79.458/105.839/121.511/15.807 msping -I wwp0s20u1u1u4.0 8.8.8.8 -c 4PING 8.8.8.8 (8.8.8.8) from 5.91.204.208 wwp0s20u1u1u4.0: 56(84) bytes of data.--- 8.8.8.8 ping statistics ---4 packets transmitted, 0 received, 100% packet loss, time 3023msUPDATE:With a QMI modem that exposes 2 RMNETs this very same configuration works. I wonder how to debug the VLAN network of this use case.
Routing Mobile connections for multiple uplinks
networking;routing;lte