Can someone confirm these days - 2016 - 2017 ? Best with https://github.com/iputils/iputils
Thank you! -- You received this bug notification because you are a member of Desktop Packages, which is subscribed to iputils in Ubuntu. https://bugs.launchpad.net/bugs/82720 Title: ping doing LOTS of useless dns request Status in iputils package in Ubuntu: Confirmed Bug description: Description: When the user is doing "ping -f myhostname.tld", ping does a ipaddr->hostname request at EACH packet. Which is quite a lot when used with a -f option. Moreover it is quite useless as when used with -f, ping doesnt display the result of the ipaddr->hostname, but only a single dot per packet. - I discovered this when implementing a nss plugin (/etc/nsswitch.conf kindof stuff). - I dunno the actual impact of this, just seems like very inefficient. - But if the nss plugin doesn't have an request cache, this will become quite a denial of service for this service -gjarboni's addition-- Actually, this can be a lot worse in certain cases. For example, try pinging dnstest.bigjar.com. You can't reproduce this in text but what happens is: Pinging machine sends out ICMP echo request Pinging machine sends out in-addr.arpa DNS query (ip address -> DNS name) Pinging machine receives NXDOMAIN (no such record) from DNS server ------ 5 to 10 seconds pass ------ Pinging machine prints: 64 bytes from 12.173.97.1: icmp_seq=1 ttl=252 time=20.9 ms This happens for every packet. If you interrupt ping during the 5 to 10 second period it will print the "64 bytes from ..." bit before returning to the shell prompt. I shudder to imagine someone trying to walk a user through testing connectivity with this bug. It also occurs in Debian 4.0. I have packet traces and a much more detailed write up if anyone is interested. This bug doesn't happen with all IP addresses that don't have a hostname associated with them, just certain ones, but it appears to specific to certain name servers. To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/iputils/+bug/82720/+subscriptions -- Mailing list: https://launchpad.net/~desktop-packages Post to : desktop-packages@lists.launchpad.net Unsubscribe : https://launchpad.net/~desktop-packages More help : https://help.launchpad.net/ListHelp
