I am running my mail server on Ubuntu Server 10.10 x64.
It seems from time to time my mail log is recording this message :
Dec 7 07:50:59 evilbox dccproc[1175]: no working DCC servers dcc1.dcc-servers.net dcc2.dcc-servers.net dcc3.dcc-servers.net ... at 127.0.0.1 Dec 7 07:55:12 evilbox dccproc[1175]: no working DCC servers dcc1.dcc-servers.net dcc2.dcc-servers.net dcc3.dcc-servers.net ... at 127.0.0.1
Running cdcc info gives this :
# cdcc info
# 12/07/11 09:42:21 EET /var/dcc/map # Re-resolve names after 11:31:25 Check RTTs after 09:46:25 # 1 total, 0 working servers IPv6 on version=3 dcc1.dcc-servers.net,- RTT+1000 ms anon # undefined name or wrong IP version dcc2.dcc-servers.net,- RTT+1000 ms anon # undefined name or wrong IP version dcc3.dcc-servers.net,- RTT+1000 ms anon # undefined name or wrong IP version dcc4.dcc-servers.net,- RTT+1000 ms anon # undefined name or wrong IP version dcc5.dcc-servers.net,- RTT+1000 ms anon # undefined name or wrong IP version @,- RTT-1000 ms 32768 secret1234567890 # *127.0.0.1,- # not answering ################ # 12/07/11 09:42:21 EET greylist /var/dcc/map # Re-resolve names after 11:42:21 Check RTTs after 09:57:21 # 1 total, 0 working servers # continue not asking greylist server 32 seconds after 1 failures @,- Greylist 32768 secret1234567890 # *127.0.0.1,6276 # not answering
Apparently it can’t contact dcc1.dcc-servers.net / dcc2.dcc-servers.net / dcc3.dcc-servers.net / etc.
Running telnet dcc4.dcc-servers.net 6277 , connects me to the specified server, but running again cdcc info gives the same result as above.
To resolve this , run cdcc rtt.
Sample of output:
# cdcc rtt
# 12/07/11 09:45:42 EET /var/dcc/map # Re-resolve names after 11:44:50 Check RTTs after 10:00:41 # 1256.98 ms threshold, 1235.85 ms average 12 total, 11 working servers IPv6 on version=3 dcc1.dcc-servers.net,- RTT+1000 ms anon # 200.81.186.149,- SION ID 1111 # 100% of 1 requests ok 379.30+1000 ms RTT 100 ms queue wait # 209.169.14.26,- x.dcc-servers ID 104 # 100% of 1 requests ok 288.80+1000 ms RTT 100 ms queue wait # 209.169.14.29,- x.dcc-servers ID 104 # 100% of 1 requests ok 276.54+1000 ms RTT 100 ms queue wait
From the documentation
RTT [−N]measures the round trip time to the DCC servers. It does this by discarding accumulated information and forcing a probe of all listed server IP addresses.
Beware that when run with sufficient privilege, the RTT operation is like the info and load operations and displays cleartext passwords.
−N displays the reverse DNS name of each server.
After that, running cdcc info will produce valid results and DCC will work as it should.
1 comments
very helpful, thank you for the info !