arping script to fix WAN drops

[illogos]

I have been running into an issue with my GT-AX6000 with a Comcast XB7 in bridge mode. Intermittently, I'll get every other ping to drop, which kills pretty much everything on the network (2.4 and 5). The router is able to ping and trace route just fine. The modem is also to ping and trace out too. I noticed a lot of posts regarding the XB7 needing an arp every few minutes. SSH issuing an arping to the default gateway comcast ip would fix the issue. Here is what I have set:

I created /jffs/scripts services start

#!/bin/sh

/usr/sbin/cru a ap "*/4 * * * * arping -c 1 71.194.216.1"

Then:
chmod a+rx /jffs/scripts/services-start
I then enabled scripts in the web ui and rebooted the router.

cru l shows
*/4 * * * * arping -c 1 71.194.216.1 #ap#

I'm new to all this so I just want to make sure I set this up right? This will arping the gateway every 4 minutes?

 

[ColinTaylor]

Yes, that is correct. I suggest you add the -q parameter as the output from the cron job has nowhere to go.

/usr/sbin/cru a ap "*/4 * * * * arping -qc 1 71.194.216.1"

 

[illogos]

Thank you, will do.

 

[dave14305]

Another tweak may be to always get the gateway IP from nvram in case it changes.

/usr/sbin/cru a ap "*/4 * * * * arping -qc 1 \$(nvram get wan_gateway)"

 

[illogos]

Another tweak may be to always get the gateway IP from nvram in case it changes.

/usr/sbin/cru a ap "*/4 * * * * arping -qc 1 \$(nvram get wan_gateway)"

Great suggestion! I was hoping there was a way to put that in as a variable. I did need to change it slightly from \$(nvram.. by removing the \

 

[dave14305]

Great suggestion! I was hoping there was a way to put that in as a variable. I did need to change it slightly from \$(nvram.. by removing the \

By removing the \, you’re only getting the current gateway at the time the router boots up. Otherwise, keeping the \ makes the cron job retrieve the gateway at each execution.

Ideally, this cron addition would be added to a dhcpc-event script acting on the bound event.

 

[illogos]

By removing the \, you’re only getting the current gateway at the time the router boots up. Otherwise, keeping the \ makes the cron job retrieve the gateway at each execution.

Ideally, this cron addition would be added to a dhcpc-event script acting on the bound event.

That makes sense. I got thrown when I tried to manually run the arping -qc 1 \$(nvram get wan_gateway) and got a syntax error: unexpected "("

 

[sfx2000]

I have been running into an issue with my GT-AX6000 with a Comcast XB7 in bridge mode. Intermittently, I'll get every other ping to drop, which kills pretty much everything on the network (2.4 and 5). The router is able to ping and trace route just fine. The modem is also to ping and trace out too. I noticed a lot of posts regarding the XB7 needing an arp every few minutes.

If you take the XB7 out of bridge mode, does the problem persist?

 

[illogos]

If you take the XB7 out of bridge mode, does the problem persist?

It does not persist when the modem is not in bridge mode. The only downside there is the double nat. Putting the router in DMZ and manually disabling the modem ssids helped. I just stubbornly wanted to keep it in bridge mode.

 

[sfx2000]

It does not persist when the modem is not in bridge mode. The only downside there is the double nat. Putting the router in DMZ and manually disabling the modem ssids helped. I just stubbornly wanted to keep it in bridge mode.

Is there any reason why you don't want the XB7 just do the router stuff?

Double-NAT isn't really a big deal - and you can put the Asus device over in the DMZ if needed

 

[illogos]

Is there any reason why you don't want the XB7 just do the router stuff?

Double-NAT isn't really a big deal - and you can put the Asus device over in the DMZ if needed

The XB7 doesn’t do a great job compatibility wise with some of the more distant smart devices (lock, plugs, bulbs). Many devices failed outright when I had 1 said, but still wouldn’t work quite right even when split. Like my Feit bulbs would pull wan ip addresses through the WiFi somehow. The ASUS allows more customization of 2.4 settings for that.