Weird ping/dns behaviour, SLIP.

Weird ping/dns behaviour, SLIP.

Post by Ade Bark » Fri, 06 May 1994 00:36:39

Hi there... I'm trying to figure out what's happening with
my `ping' command. Background: my system is connected via
SLIP to OS is Microport svr4 4.2.1, 486.

My system is configured to resolve addresses using DNS,
acting as a client to a Colorado SuperNet machine. Here's
a typical ping result, with major packet losses:

----slate.Mines.Colorado.EDU PING Statistics----
5 packets transmitted, 2 packets received, 60% packet loss
round-trip (ms)  min/avg/max = 260/720/1180

However, if I put slate's address into my /etc/hosts file,
everything works fine.. the packet losses disappear: PING Statistics----
5 packets transmitted, 5 packets received, 0% packet loss
round-trip (ms)  min/avg/max = 290/300/340

The phenomenon is only observed for `ping'. Other programs
like `ftp' appear to be working fine, regardless if the
host is in /etc/hosts or not.

Why does this happen ? Is `ping' trying to use the DNS
resolver before sending each packet, and it's taking too
long ?

Thanks in advance,

-Ade 'clueless' Barkah


1. Weird Ping, weird FTP, weird Telnet... HELP!!!

Can anyone diagnose this for me?

I'm in the process of building up a firewall but at some stage I musta
messed up and am now getting really weird results.

This is the results of a ping from to (the box
which will become the fireawall).

PING ( from : 56(84) bytes of
64 bytes from icmp_seq=0 ttl=225 time=0.7ms
64 bytes from icmp_seq=1 ttl=225 time=80001.0ms
64 bytes from icmp_seq=2 ttl=225 time=160000.9ms
64 bytes from icmp_seq=3 ttl=225 time=240000.8ms
64 bytes from icmp_seq=4 ttl=225 time=320000.8ms
64 bytes from icmp_seq=5 ttl=225 time=400000.7ms
64 bytes from icmp_seq=6 ttl=225 time=480000.7ms


--- ping statistics ---
509 packets transmitted, 8 packets received, 98% packet loss
round-trip min/avg/max = 0.7/280000.7/560000.6 ms

This also happens when I do it from other machines behind the firewall
but I was very surprised when it did it when pinging itself.

Theres a pattern of 80000ms increments between successful pings...
Can't figure out whats wrong though.

If I try to telnet or FTP, I have to wait for an eternity b4 the login
prompt appears after the initial "connected" msg. But once I login
there is no problem using the console or transferring files. Same
thing for other machines to So the network is "working"
but its waiting for something.

Has anyone had this happen to them b4 and manage to solve it?

Any help appreciated


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