SD-WAN

Currently to get our PPPoE connections to work, the ISP has to have them set to DHCP, and we have to manually update all adjacency any time the modem receives a new IP address. The DSL modems are set to bridge mode, so our routers do the PPPoE authentication with the ISP. ¾ From my understanding, I believe that version 3.2.x PPPoE handling by 128T has been updated, and 128T will now be able to automatically update adjacencies when it receives a different IP address. ¾ What do I need to change in the configuration for the device interface, do start utilizing this feature?

Hi Austin Stoffel ! There are two pieces to it.

 

First, you need to set up configuration for ""dynamic-hostname"" in your authority. The help text suggests some configuration for it. Here's what my lab system uses:

config ¾ authority name beaconnet dynamic-hostname intf-{interface-id}.{router-name}.{authority-name}

This new ""dynamic-hostname"" field lets you construct a map of sorts... now, all interfaces that get their address dynamically (DHCP, PPPoE, LTE, etc.) will have a pseudo-hostname generated for them by the routers, and that pseudo-hostname will be constructed using this template (e.g., intf-0.labsystem2.beaconnet is one of the hostnames in my lab).

 

The second part is to change the adjacencies that point to the router that has a dynamic address to use this hostname instead of an IP address. Important note: you're not changing any adjacencies on the router with the dynamic address... you're changing the configuration on the ones that send traffic to it. The easiest way to do this, assuming you've set up neighborhoods already, is to set the generated flag to true on the adjacency with this router. This will cause that service-route to get deleted and re-generated using the dynamic hostname following the rules above.

 

If you haven't set up neighborhoods, you'll need to set up the adjacency's IP address using this pseudo-hostname manually:

adjacency intf-0.labsystem2.beaconnet ip-address intf-0.labsystem2.beaconnet peer newton inter-router-security interfabric exit

If you want to copy/paste some configuration bits here to make sure you're doing it correctly, feel free. (Scrub any info you feel might be sensitive!)

Thanks, PT! I tried this out yesterday at one location, and it looks like I've got it working. Looks like there are a couple of extra cleanup steps afterward to delete the old, manually created adjacencies.

 

If the site I tested it on has some downtime this afternoon, I'm going to try testing it out. I'll have someone reboot the DSL modem, to force it to take a new IP, verify it has a different IP address. Then have them take down other ISP and we'll see if the DSL PPPoE peers stay up.

 

Thanks.

We tested it out and it worked!