Malformed name, or illegal name

John Aasen john.aasen at
Wed May 22 01:07:31 EST 2002

We have got a problem with our Linux NIS+ clients.

When running on 10Mbps Ethernet they work mostly fine, but when upgrading to 
100 Mbps Ethernet I start getting a lot of 'Malformed name, or illegal name' 
messages when running niscat passwd.org_dir. The command normally succeeds 
one of 10 times. I also observer that some commands where username lookup 
etc. are involved take longer time than normal.

The NIS+ server is a Solaris machine (SunOS 5.7) on a 10Mbps network.

I have seen the same with nis-utils 1.3 and 1.4.1.

I have found two ways of reducing the frequency of failed niscat executions:
1. Use mii-tool to force the network tu run an 10Mbps
2. run strace niscat passwd.org_dir

I guess there might be a race condition soemwhere in the code.

I attach a part from a tcpdump that comes when the niscat command fails.
15:09:51.714554 > [client].33544 > [server].32773: udp 108 (DF)
15:09:51.715076 < [server].32773 > [client].33544: udp 24 (DF)
15:09:51.715086 > [client] > [server]: icmp: [client] udp port 33544 unre
achable [tos 0xc0]

On the first line the clinet sends a packet from port 33544, the server 
answers, but it looks like the client has closed the port before the reply 
comes. In the last line the client says that udp port 33544 is unreachable.

I am in no way an expert in sockets and understanding tcpdump, so I may be 
completely wrong in my interpretation.

Has anyone seen this behaviour before and got any solutions to how I can get 
past it?


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