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Emerging Member
Posts: 58
Registered: ‎02-14-2015
Kudos: 1

Weird issue after changing from Ethernet -> SFP port for LAN

Hi,

I have a ER-4 which was working fine but i wanted to play with SFP. I had following:

 

WAN -> eth0

LAN -> eth1

 

The eth1 was connected to a UniFI switch. Everything was working fine. I then decided to use eth3 for LAN so i enabled it and gave the same ip i had on eth1 but gave eth1 new ip. Everything looked ok. I made the changes and commited then saved. I then disabled the other end of eth1 going to the UniFi e.g i disabled the port on the switch so i only used SFP port. Everything was working fine. After a week or so i did a power cycle of both EdgeRouter and UniFi switch then the internet behind eth3 was not working anymore. I was getting ip's but could not ping the gateway on eth3 (SFP port) and neither could i get in contact with the router on SSH so i then enabled the port on the UniFI again and contacted the router on SSH on the new ip i gave interface eth1 and that worked, i then did some ping to google, that worked fine and then i did a reboot from CLI, when the router came back the internet was working fine so i disablet the ethernet port again on the UniFi and to my suprise the internet still worked. That puzzled me the first time then i forgot about it. Yesterday same happened again so no coincidence. Any ideas what might be the problem ? Is there a bug with SFP port on one end or the sequence how things start up or ???

 

I have attached my config both before and after, if you use a text compare tool it's quite easy to see the changes i made when i went from Ethernet eth1 to SFP eth3.

 

/donnib

Emerging Member
Posts: 58
Registered: ‎02-14-2015
Kudos: 1

Re: Weird issue after changing from Ethernet -> SFP port for LAN

I'd like to give an update, today no machines on LAN could get IP address and no reboot were made so i pulled out the SFP cable and plugged it back again and then things started to work. It seems to me there is somekind o instability with the SFP port ?

 

I would be nice if somebody could reply to this so i know if this i a bug or configuratino issue.

Regular Member
Posts: 716
Registered: ‎06-17-2015
Kudos: 146
Solutions: 43

Re: Weird issue after changing from Ethernet -> SFP port for LAN

[ Edited ]

You cant use the same subnet over two physical interfaces, unless they are bridged:

 

ethernet eth1 {
address 10.10.0.3/24
description Internal_LAN
duplex auto
speed auto
}

}
ethernet eth3 {
address 10.10.0.1/24
description Internal_LAN
duplex full
speed 1000

 

 

EDIT: I didnt see any listen-on ports on DNS for DHCP 

Emerging Member
Posts: 58
Registered: ‎02-14-2015
Kudos: 1

Re: Weird issue after changing from Ethernet -> SFP port for LAN

@nu2ubiq thank you for taking the time to reply :

 

So what should i set the other interface to ? I am afraid to change in case i have problems again then i don't know how to get in contact with it again. Do you think this could be the problem?

 

I checked the config and i have following: 

 

dns {
        forwarding {
            cache-size 150
            listen-on eth3
            listen-on vtun0
        }

I guess this should cover it ? 

Regular Member
Posts: 716
Registered: ‎06-17-2015
Kudos: 146
Solutions: 43

Re: Weird issue after changing from Ethernet -> SFP port for LAN

Probably better to console in and change the subnet on one of your ports, that way you wont lose connection with the router. Thats probably what I would do. Perhpas someone will chime in with another option.

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