Just says 'registering'... we did a packet trace and it just shows an invite and a couple of refers, but no responses to it...
Jonathan On Fri, Apr 24, 2015 at 4:34 PM, Ryan Huff <[email protected]> wrote: > Are you able to see the physical phone during the event? What is the > physical phone's behavior? > > Does the physical phone show un regestered or does the phone show the new > ccm/tftps addresses eventhough it doesn't register? > > Whst load version on the 8851's? > > Thanks, > > Ryan > > > -------- Original Message -------- > From: Jonathan Charles <[email protected]> > Sent: Friday, April 24, 2015 04:19 PM > To: "Chris Ward (chrward)" <[email protected]> > Subject: Re: [cisco-voip] Cisco 8851 not failing over to backup circuit... > CC: [email protected] > > Cranked the MTU to 1500, no change, dropped it down to 1100, no change... > they will not register over the backup link... we have confirmed full > connectivity over this link... > > > Jonathan > > On Fri, Apr 24, 2015 at 11:22 AM, Chris Ward (chrward) <[email protected]> > wrote: > >> VPN registration issues usually point to MTU issues. Or at least packet >> or fragments due to MTU issues. I suspect there is a different in packet >> size during the registration of these two devices or capabilities that >> affects packet size. >> >> >> >> When the primary link is down, you could run some ping tests while >> setting the ping size to 1X00 and setting the DF bit as well, this will >> help you find the max size packet with overhead that can fit over the >> tunnel. Typically VPN tunnels take at least 80 bytes of overhead, so the >> largest MTU I would expect you could fit over the tunnel would be 1420. >> >> >> >> I would try and adjust your tunnel MTU down to 1400 or even 1300 just as >> a test to see if it helps. (In my demo setups with EZVPN tunnels, I can >> only use 1350 max) Also, are your VPN endpoints able to fragment packets or >> clear DF bits so that they can fragment large packets? If you can clear >> df-bit at the interface, that may help move some of the larger packets >> through IF they have the DF-bit set. >> >> >> >> +Chris >> >> TME - Unity Connection and MediaSense >> >> >> >> *From:* cisco-voip [mailto:[email protected]] *On >> Behalf Of *Jonathan Charles >> *Sent:* Friday, April 24, 2015 11:44 AM >> *To:* Charles Goldsmith >> *Cc:* [email protected] >> *Subject:* Re: [cisco-voip] Cisco 8851 not failing over to backup >> circuit... >> >> >> >> MTU was set to 1440, we set it to Auto, no change... >> >> >> >> >> >> >> >> Jonathan >> >> >> >> On Thu, Apr 23, 2015 at 10:13 PM, Charles Goldsmith <[email protected]> >> wrote: >> >> What's your MTU over the backup VPN? I've seen odd issues on some >> networks with different providers and MTU and fragmenting packets >> always caused issues until the MSS was set. >> >> I'm not sure why this would affect the 8851's, but we've noticed some >> other oddities with the 8851's. For instance, computers with intel >> nic's behind the phone have issues after we apply config, and we >> narrowed it down to intel gigabit master slave mode setting on the >> driver, at least, setting that to slave instead of auto resolves the >> problem. Otherwise, you have to reboot the phone a couple of times to >> get consistent connection through the 8851. Phones are connected to a >> 2960 with a basic config, nothing out of the ordinary. >> >> >> On Thu, Apr 23, 2015 at 6:35 PM, Jonathan Charles <[email protected]> >> wrote: >> > We have CUCM 8.6.2 with Cisco 8851, Cisco 8831 phones at a remote >> location; >> > they are connected over MPLS and a Peplink Balance VPN as a backup. >> > >> > When we yank the MPLS, the 8831 registers with CUCM and works fine.... >> the >> > 8851s do NOT. >> > >> > Any reason the 8851 would act differently? >> > >> > >> > >> > >> > Jonathan >> > >> >> > _______________________________________________ >> > cisco-voip mailing list >> > [email protected] >> > https://puck.nether.net/mailman/listinfo/cisco-voip >> > >> >> >> > >
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