Tag Archives: ccna

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

Poor Man's Spanning Tree

Click for full-sizeLate on in my CCNA studies, I came across the Network Bridge facility in Windows XP. This creates a bridge that supports IEEE 802.1D Spanning Tree. Curiosity got the better of me and I decided to investigate  and see how it interacted with the spanning-tree on my Catalyst switches. If you’re stuck with only one switch but have a PC with two ethernet NICs then you can do some spanning tree checks. Continue reading

CCNA Complete!

On an extremely cold January 5th, I made my first attempt at the 604-816 ICND2 exam at Edison Community College, Piqua, Ohio.

I managed to astound myself by passing with a score of (!!!). That’s CCNA completed, now I have to decide which cert to do next.

RIP Quirks

As I understood it…

The default for RIP when it is enabled is to send version 1 and receive both versions 1 and 2. Then I got a practice question with a #debug ip rip output with the following line:

1d12h: RIP: ignored v2 packet from 10.1.1.1 (illegal version)

RIP practice question

Completely threw me, so I went back to my lab and discovered that you can also
configure RIP for version 1 only so it will reject V2 packets –

(config-router)#version 1 – Sure enough the output of #show ip protocols confirmed
this! Continue reading

PPP Multilink

I wanted to find out a bit more about how to configure and test ppp multilink (ppp over parallel links). It gets a mention in ICND2 but nothing specific on configuration. I’ve encountered it before for ISDN dial-ups from Congo and Zyxel routers so naturally I’m curious to see how it’s done the Cisco way. Multilink ppp balances the traffic equally over the links at layer 2 whilst allowing the layer 3 in each router to treat the parallel links as a single link. Continue reading

CCNA

CCNA Lab I’ve been slowly progressing through CCNA for a while now, proof that you can teach an old dog new tricks. ICND1 was mainly basic theory and an introduction to Cisco IOS command line – I surprised myself by passing 604-822 at the first attempt.

Here is my lab – a selection of switches and routers. These should allow me to do all the simulations I need for ICND part 2 and maybe beyond…

I’ve learned and implemented some new (to me) concepts from this, although practical applications have not been with Cisco equipment, I’d prefer to call them vendor neutral so far. The most interesting project was converting  a FreeBSD ntp server that used multiple network cards.  I updated this to use 802.1Q tagged vlans using an Allied Telesyn switch.

I’ve even discovered that you can do RIP and OSPF routing in Windows :0