netKb Research Activities:
If you have a packet trace you'd like analyzed, see netKB Submission Process
To see examples cases of how various protocols work normally see: Protocol Library
Here are examples of protocol violations and various network problems:
| Date | Document | Description |
|---|---|---|
| 2001-04-12 | Alcatel Duplicate IP |
Since all Alcatel ADSL modems have the same management IP address (10.0.0.138) this creates some real ARP fun. |
| 2001-03-20 | IFITL Congestion Collapse |
Severe congestion (buffer overflow?) causes thoughput collapse when communicating with a fast, local server. Such that even Fast retransmits are lost causing congestion backoff delays of 4000ms. Throughput drops from 2-3Mbps to 400Kbps. |
| 2001-03-16 | ATL Newserver down | Responds to all connect requests with TCP Reset (RST) |
| 2001-03-16 | BHM Cache Server Dead (fcs00bhm) | Accepts connections and requests, but never responds to them |
| 2001-03-12 | ARP Timeout | An example of a *compliant* yet poor ARP implementation |
| 2001-02-28 | Passive (PASV) FTP uploads to WARFtp server failing | Server seems to accept client data but ignores FIN included in last data packet |
| 2001-02-27 | SonicWall DHCP Renew Failure | Case where SonicWall fails DHCP renew when DHCP server is not on local subnet |
| 2001-02-27 | Primary DNS Server Failed | Here's why surfing get can real slow if your Primary DNS server isn't working (even if the secondary is) |
| 2001-02-23 | ICS FTP Port Command Bug | ICS adds supurious <CR> (0x0D) when sending FTP PORT command causing War-FTP servers (and possible others) to fail with Error 500: 'dunno how to interpret empty lines' |