Network traffic problem ---- packet loss

Hi, I have setup a complicated network as the following:

(SiteA)PIX506E ---> (SiteB)[PIX515E + Router1 ] ----> SiteC[Router2 + LAN ]

  1. SiteA + SiteB = VPN Tunnel
  2. SiteB + SiteC = Routable Traffic
  3. Traceroute and ping are working properly between tree sites.
  4. domain name can be resolved between sites

I found that some packets lost ( from SiteA --> SiteC ), and the packet can not be retransmitted; But the packet can be retransmitted between SitA --> SiteB;

The packet captured as the following :

  1. Packet can not be retransmitted ( SiteA -> SiteC ):

Source Destination Protocol information

172.27.29.80 172.28.0.99 SSLv2 Client Hello 172.28.0.99 172.27.29.80 SSL [TCP Previous segment lost] Continuation Data

172.27.29.80 172.28.0.99 TCP [TCP Dup ACK 178#1] 2161 > https [ACK] Seq=79 Ack=1 Win=65535 Len=0 SLE=1381 SRE=2223

172.28.0.99 172.27.29.80 TCP https > 2161 [RST, ACK] Seq=2223 Ack=79 Win=0 Len=0

  1. Packet can be retransmitted ( SiteA -> SiteB ):

172.27.29.80 172.27.1.13 SSLv2 Client Hello 172.27.1.13 172.27.29.80 SSLv3 [TCP Previous segment lost] Continuation Data, [Unreassembled Packet]

172.27.29.80 172.27.1.13 TCP [TCP Dup ACK 215#1] 2223 > https [ACK] Seq=79 Ack=1 Win=65535 Len=0 SLE=1381 SRE=1548

172.27.1.13 172.27.29.80 SSLv3 [TCP Retransmission] Server Hello, Certificate[Unreassembled Packet]

172.27.29.80 172.27.1.13 TCP 2223 > https [ACK] Seq=79 Ack=1255 Win=64281 Len=0 SLE=1381 SRE=1548

172.27.1.13 172.27.29.80 SSLv3 [TCP Retransmission] Continuation Data, [Unreassembled Packet]

172.27.29.80 172.27.1.13 SSLv3 Client Key Exchange, Change Cipher Spec, Encrypted Handshake Message

172.27.1.13 172.27.29.80 SSLv3 Change Cipher Spec, Encrypted Handshake Message

Anybody has idea what the problem happened to the network ?

  1. the Router blocks the packet transmission
  2. The firewall blocks the packet transmission
  3. the vpn tunnel blocks the packet transmission
  4. the MTU value between firewalls ?
  5. The VPN configuration has problem ?
  6. others

Thank you so much for your input. Benson

Reply to
bensonlei
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Hi Benson,

funny you should mention this. I've also just started seeing a similar problem. Though from internet clients to an SSL webserver. Again it's also via a PIX.

Odly enough, it only happens with SSLv3 and TLS. SSLv2 seems to work just fine.

Also oddly enough, it's happening for just one site on the server and not any of the others.

My server is however NT4 with IIS. Have you gottent a response from anyone?

Thanks Craig

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Reply to
Craig

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