Re: [OT] Ping mystery
Hi On Sat, Nov 02, 2013 at 01:09:31PM -0400, Brad Alexander wrote: > I have sort of a weird one here. On my network, I have my firewall, which has > 3 > interfaces. eth0 to the internal network, eth1 to the DMZ with a wireless > access point hanging off of it, and eth2 out to the interwebs. > > My workstation is on the internal network, and i have a Nokia N900 on the > wifi. > I saw in the backup reports that the Nokia failed to back up because of long > ping times. So I pinged it, and while every ping came back, and the "time=" > looked normal, it was running at about 1/3 speed. I tried a combination of > pings and found the following: > > * Pings from my workstation to the Nokia by hostname are slow; > * Pings from the firewall are normal; > * Pings from the access point are normal; > * Pings from the workstation by IP are normal. > > Now, I thought it might be an issue on my dns. It wasn't. The DNS responds > normally with 1msec query times. Hm... I'd suggest to take DNS out of the equation by: * Make sure all pings are done by IP address, rather than DNS Name * Use the -n option on ping to avoid the reverse DNS lookup... Hope this helps -- Karl E. Jorgensen -- To UNSUBSCRIBE, email to debian-user-requ...@lists.debian.org with a subject of "unsubscribe". Trouble? Contact listmas...@lists.debian.org Archive: http://lists.debian.org/20131102194748.GA29269@hawking
Re: [OT] Ping mystery
Brad Alexander wrote: > I have sort of a weird one here. On my network, I have my firewall, > which has 3 interfaces. eth0 to the internal network, eth1 to the DMZ > with a wireless access point hanging off of it, and eth2 out to the > interwebs. > My workstation is on the internal network, and i have a Nokia N900 on > the wifi. I saw in the backup reports that the Nokia failed to back up > because of long ping times. So I pinged it, and while every ping came > back, and the "time=" looked normal, it was running at about 1/3 > speed. I tried a combination of pings and found the following: > * Pings from my workstation to the Nokia by hostname are slow; > * Pings from the firewall are normal; > * Pings from the access point are normal; > * Pings from the workstation by IP are normal. > Now, I thought it might be an issue on my dns. It wasn't. The DNS responds > normally with 1msec query times. What DNS queries did you test? Name-to-IP or IP-to-name? I once experienced strange ping slowness, because ping was trying to reverse-resolve the IP of the returned ICMP package every time. The slowness was caused by a misconfigured bind, refusing to answer the request, causing a 5 second delay every time. Grüße, Sven. -- Sigmentation fault. Core dumped. -- To UNSUBSCRIBE, email to debian-user-requ...@lists.debian.org with a subject of "unsubscribe". Trouble? Contact listmas...@lists.debian.org Archive: http://lists.debian.org/0a666jao0...@mids.svenhartge.de
