Hurricane Electric's IPv6 Tunnel Broker Forums

General IPv6 Topics => IPv6 on Linux & BSD & Mac => Topic started by: rdk on December 24, 2017, 01:14:02 PM

Title: IPv6 tunnel delays, CentOS 7
Post by: rdk on December 24, 2017, 01:14:02 PM
Hi!

I recently changed way too many variables and now my IPv6 HE tunnel has very very high delay (~750 ms).

I changed ISPs from Charter to AT&T for fiber speeds and I built a new router and installed Centos 7 (was FC17).

Tunnel is up and working but when I ping across it, I see delays on order of 750ms.

IPv4 traceroute to my tunnel endpoint shows 38ms delay.

IPv4 traceroute to my tunnel endpoint with proto=41 shows delay about 30ms.

This leads me to conclude that its something getting groked in my CentOS7 box.

Any suggestions or pointers as to what might be causing these large delays?  My configuration is fairly similar to my old box.  One small change though is that my external interface is a non-routable subnet to my modem.  I don't believe my modem is introducing the delays because of the traceroute data above.

Thanks,

Bobby
Title: Re: IPv6 tunnel delays, CentOS 7
Post by: rdk on January 18, 2018, 04:11:37 PM
Hi!

I placed a port-mirroring switch between my centos/linux router and my AT&T modem.

After capturing tunnel traffic, I have concluded that the delay is NOT being introduced by my CentOS/Linux router.  The delay is being introduced either by the modem or by AT&T backbone.  Most likely, its the modem.

Ugh.

Bobby
Title: Re: IPv6 tunnel delays, CentOS 7
Post by: rdk on May 21, 2018, 04:31:53 PM
Hi!

I'm happy to report that switching modems solved the problem!  I got rid of the ARRIS BGW210 AT&T modem and got a Pace 6268AC modem and the IPv6 tunnel delay disappeared.

My HE ipv6 tunnel now works fine with no appreciable delay.

Bobby