In a CRS212 we have 2 SFP 1G links coneccted.
Both fibers links OK. We want to connect in the swtich (not via CPU) a tagged VLAN (802.1q) between both ports.
We do the things as in the CRS manual example but we have problems with the ARP request between both sides, and with the traffic.
sfp1 is a slave of sfp2 port. Same tagged vlan on both.
IP 10.1.1.1/30 and 10.1.1.2/30 on the each side.
We can’t get the ARP of the router in the other side. but CDP (Cisco Discovery protocol) seems to work, If we ping the broadcast address (ping 10.1.1.3 from 10.1.1.1) in the debug we see a reply from 10.1.1.2, but no ARP resolves for 10.1.1.1.
If we set a static ARP with the corresponding mac address, we can ping with no problems (with packets bigger than 1500 bytes even, so MTU problem) but a telnet doesn’t work, it connects after a little while but couldn’t follow up to the limit of not getting the login prompt.
If we shutdown one of the SFP ports, and set a VLAN interface with the corresponding IP of the router that was on that fiber in the CRS VLAN port created, and then we set in the middle like if we where the other router on the other SFP port, we have connection with no issue.
Via bridge interface it works ok also. If we don’t link both ports (both with Master port set to none), and we set a VLAN interface associated to sfp1 and other VLAN interface asocciated to sfp2, and both VLAN interfaces linked into a bridge port, it works perfect.
So it’s like for some reason the switching isn’t working propertly or something like that happens. But the conection between the ports and to CPU (switch1-cpu interface on the swith) is ok.
We tried with router OS 6.28 that was in the CRS, and with the latest one available. Any ideas? Hardware problem?
That’s the config configuration now working (with the ARP problems).
/system routerboard print
routerboard: yes
model: CRS212-1G-10S-1S+
serial-number:
current-firmware: 3.19
upgrade-firmware: 3.22
/interface ethernet
set [ find default-name=sfp1 ] auto-negotiation=no master-port=sfp2 name=sfp1
set [ find default-name=sfp2 ] auto-negotiation=no name=sfp2/interface ethernet switch vlan
add ports=sfp1,sfp2 vlan-id=111 learn=yes/interface ethernet switch egress-vlan-tag
add tagged-ports=sfp1,sfp2 vlan-id=111/interface ethernet switch
set drop-if-invalid-or-src-port-not-member-of-vlan-on-ports=sfp1,sfp2
The rest of the config is the default one, just with one IP for managenet on the RJ45 port of the CRS.
And this is the working configuration via bridging instead of switching:
/interface bridge
add name=bridge111/interface ethernet
set [ find default-name=sfp1 ] auto-negotiation=no name=sfp1
set [ find default-name=sfp2 ] auto-negotiation=no name=sfp2/interface vlan
add interface=sfp1 l2mtu=1584 name=vlan111sfp1 vlan-id=111
add interface=sfp2 l2mtu=1584 name=vlan111sfp2 vlan-id=111/interface bridge port
add bridge=bridge111 interface=vlan111sfp1
add bridge=bridge111 interface=vlan101sfp2