Monthly Archives: February 2011

Cisco Console Cable Differences

The console cable RS232 lines used vary between Routers and Catalyst Switches.

  • Router console does not use RTS/CTS (pins 1 and 8).
  • Router aux port uses all pins.

Reference:
Auxiliary Port, Console Port, And Adapter Pinouts For Cisco 1000, 1600, 2500, 2600, And 3600 Series Routers

  • Some Catalyst switches do not use DSR/DTR (pins 2 and 7) but do use RTS/CTS (pins 1 and 8).

Reference:
Connecting a Terminal to the Console Port on Catalyst Switches

This solves an issue I’ve been having with connecting some Catalyst switches to my Lantronix ETS-16 terminal server – the cables are only connected to RJ45 pins 2-7. The solution is to make up a cable with 1 looped to 8 (RTS – CTS) on the RJ45.

The Cisco RJ45 – 9D-Female rollover cable works perfectly as I would expect!

Setting Your Source Interface

Problem: I’ve set up VPN between the LANs on two routers and I want to test the link from LAN 1 to LAN 3.

192.168.1.1/24--[R1]--10.1.1.0/30--[R2]--10.2.2.0/30--[R3]--192.168.3.1/24

Default ping/telnet/ssh will fail because it will use the source address of the interface closest to the destination.

R1#ping 192.168.3.1

Type escape sequence to abort.
Sending 5, 100-byte ICMP Echos to 192.168.2.1, timeout is 2 seconds:
U.U.U
Success rate is 0 percent (0/5)

Solutions: Continue reading