Linksys Routers, Reboots, and Cut-Through Forwarding (CTF)

[PowerEngineer]

I now have a better appreciation for just how much of a crapshoot router configurations can be.

My story centers around my Linksys E4200v1 router. Internet is provided through a Motorola 6121 cable modem. Two PCs are hard wired (one through power line carrier) to Ethernet ports. 1-3 laptops and two kindles connect via wireless. Aside from one of the PCs (not on power line carrier) being slow to load browser pages, everything seemed okay.

Recently we all noticed our internet connectivity was being lost every 10-30 minutes. It turns out that these connectivity loses were being caused by the E4200 which was rebooting itself. I took the obvious steps of installing the latest firmware and performing a hard reset (30-30-30), but the problem continued. I was starting to look for a replacement router.

Turning to google first, I did find out that last year others were wrestling with reboot problems on Linksys routers when connecting to some Apple devices. The best fix discovered was to disable cut-through forwarding (CTF) which by default is enabled.

Hmmm... :hmm: My wife just upgraded to an IPhone5. But surely this Apple problem was fixed in the latest firmware? Seems not!

I disabled CTF on my E4200 and now everything is working great. Even the previously slow PC is now much faster at loading pages. I also notice that streaming is much smoother. What a difference!

So, the morals of my story are that router firmware (at least from Linksys) can't be completely trusted, that default router settings are not necessarily the best, and that changes in the devices being connected can affect router performance.

Maybe my adventure will help someone else...

 

[Mushkins]

The linksys brand just hasn't been as rock solid reliable as it was in the WRT54G days. They've cut a lot of corners to keep their SOHO routers as cheap as they are, not to mention the brand being sold to Belkin a while back. Across the board the default SOHO router firmwares kinda suck, really. These days I tend to buy higher end ASUS routers and put Tomato or DDWRT on them, its just easier and more stable.

 

[florihupf]

Just signed up to be able to post a BIG THANK YOU!

I was having the same problems out of a sudden at home and the same scenario (Apple products, random reboots).

THANKS AGAIN! ;-)

 

[Emulex]

CTF can jam up switches if wifi clients manage to get into the ethernet with corrupt packets or there is any noise since CTF forwards damaged ethernet packets down the switch buffer (and perhaps out again).