1
votes

When I try to use Firefox to access an internal website http://10.168.25.1:3080/, the browser shows spinning wheel, no content appear.

  1. telnet tested, IP 10.168.25.1 and port 3080 is OK.
  2. System Solaris 10.
  3. Some other computer can Firefox or IE to this URL with expected page content (some java applet).
  4. Another computer with Windows also same issue with Firefox or IE

Snoop "snoop -o ema1.pcap 10.168.25.1" result:

No. Time Source Destination Protocol Length Info 1 0.000000 10.82.14.173 10.168.25.1 TCP 66 48126→3080 [SYN] Seq=0 Win=49640 Len=0 MSS=1460 WS=1 SACK_PERM=1

Frame 1: 66 bytes on wire (528 bits), 66 bytes captured (528 bits) Ethernet II, Src: HewlettP_c0:ee:50 (c4:34:6b:c0:ee:50), Dst: ExtremeN_82:0d:b5 (00:04:96:82:0d:b5) Internet Protocol Version 4, Src: 10.82.14.173, Dst: 10.168.25.1 Transmission Control Protocol, Src Port: 48126, Dst Port: 3080, Seq: 0, Len: 0

No. Time Source Destination Protocol Length Info 2 0.248140 10.168.25.1 10.82.14.173 TCP 66 3080→48126 [SYN, ACK] Seq=0 Ack=1 Win=14600 Len=0 MSS=1460 SACK_PERM=1 WS=128

Frame 2: 66 bytes on wire (528 bits), 66 bytes captured (528 bits) Ethernet II, Src: ExtremeN_82:0d:b5 (00:04:96:82:0d:b5), Dst: HewlettP_c0:ee:50 (c4:34:6b:c0:ee:50) Internet Protocol Version 4, Src: 10.168.25.1, Dst: 10.82.14.173 Transmission Control Protocol, Src Port: 3080, Dst Port: 48126, Seq: 0, Ack: 1, Len: 0

No. Time Source Destination Protocol Length Info 3 0.248156 10.82.14.173 10.168.25.1 TCP 54 48126→3080 [ACK] Seq=1 Ack=1 Win=49640 Len=0

Frame 3: 54 bytes on wire (432 bits), 54 bytes captured (432 bits) Ethernet II, Src: HewlettP_c0:ee:50 (c4:34:6b:c0:ee:50), Dst: ExtremeN_82:0d:b5 (00:04:96:82:0d:b5) Internet Protocol Version 4, Src: 10.82.14.173, Dst: 10.168.25.1 Transmission Control Protocol, Src Port: 48126, Dst Port: 3080, Seq: 1, Ack: 1, Len: 0

No. Time Source Destination Protocol Length Info 4 0.248223 10.82.14.173 10.168.25.1 HTTP 339 GET / HTTP/1.1

Frame 4: 339 bytes on wire (2712 bits), 339 bytes captured (2712 bits) Ethernet II, Src: HewlettP_c0:ee:50 (c4:34:6b:c0:ee:50), Dst: ExtremeN_82:0d:b5 (00:04:96:82:0d:b5) Internet Protocol Version 4, Src: 10.82.14.173, Dst: 10.168.25.1 Transmission Control Protocol, Src Port: 48126, Dst Port: 3080, Seq: 1, Ack: 1, Len: 285 Hypertext Transfer Protocol

No. Time Source Destination Protocol Length Info 5 0.494740 10.168.25.1 10.82.14.173 TCP 60 3080→48126 [ACK] Seq=1 Ack=286 Win=15744 Len=0

Frame 5: 60 bytes on wire (480 bits), 60 bytes captured (480 bits) Ethernet II, Src: ExtremeN_82:0d:b5 (00:04:96:82:0d:b5), Dst: HewlettP_c0:ee:50 (c4:34:6b:c0:ee:50) Internet Protocol Version 4, Src: 10.168.25.1, Dst: 10.82.14.173 Transmission Control Protocol, Src Port: 3080, Dst Port: 48126, Seq: 1, Ack: 286, Len: 0

No more network communication

2

2 Answers

0
votes

snooped from client and server, client's HTTP request successfully reached server, but server's HTTP response was being sending back, like some network issue blocked the response.

0
votes

This is a post from a long time ago but something to notice is that RTT is ~250ms. If the response from server is long, like a few MB's, it might take a long time to arrive. If you look at the advertised window from client 10.82.14.173, the advertised window is only 49KB which is not enough if the server is sending a response of some MB's with this latency. The time for the response to arrive could be more 250ms * 20 = 5sec for only 1MB. If it's 6MB or more, it will take +30sec and the web browser may be timing out.