WU-FTP slow in connecting up
Posted on 2005-04-18
I am running WU-FTP on a linux box( rmstreamer) RedHat 7.1 with 2 network cards.
One ATM-25 card connection to the external network via a XYLAN switch.
A ethernet nic card connection the internal network.
When connecting to the FTP server via the internal networkting there is no issue.
Connection can be established immediately. I have checked the /etc/resolve.conf and it
appears to work fine. So the problem is not with resolving.
When connecting via the ATM card from the exterior the connection takes
a long time to establish.
This is what I get
[atma@oldguard atma]$ ftp 126.96.36.199
Connected to 188.8.131.52 (184.108.40.206).
The username and password appear after approximatley 30 seconds
I have capture the tcpdump for the ATM and ethernet connections
Tcpdump - Ehternet Connection
13:47:51.045689 < 172.17.2.207.1602 > 172.17.2.202.ftp: S 2435518111:2435518111(0) win 16384 <mss 1460,nop,nop,nop,nop>(DF)
13:47:51.046087 < 172.17.2.207.1602 > 172.17.2.202.ftp: . 2435518112:2435518112(0) ack 762101979 win 17520 (DF)
13:47:51.049171 < 172.17.2.207.auth > 172.17.2.202.1278: R 0:0(0) ack 761689318 win
13:47:51.272011 < 172.17.2.207.1602 > 172.17.2.202.ftp: . 0:0(0) ack 69 win 17452 (DF)
tcpdump for the ATM card:
13:52:04.995831 < 220.127.116.11.58735 > 18.104.22.168.ftp: S 2346538258:2346538258(0) win 5840 <mss 1460,nop,nop,timestamp 1564373402 0,nop,wscale 0> (DF)
13:52:05.015831 < 22.214.171.124.58735 > 126.96.36.199.ftp: . 2346538259:2346538259(0) ack 1042881203 win 5840 < nop,nop,timestamp 1564373403 1680488> (DF)
13:52:35.115831 < 188.8.131.52.58735 > 184.108.40.206.ftp: . 0:0(0) ack 69 win 5840 <nop,nop,timestamp 15643764 08 1683492> (DF) [tos 0x10]
Once the connection has been established, the speed of upload and download is OK.
I have also removed the firewall rules on the linux box with out any success.
Could any one suggestsome pointers how to solve the problem
Thank you in advance.