Just another Cisco blog
Archive for November, 2009
Studying For The CCDA
Nov 30th
I’ve decided to get the CCDP seeing as it’s only two more exams for me (DESGN and ARCH). I’ve already finished BSCI and BCMSN for the CCNP. I’ve always had interest in design and I figure this couldn’t hurt on my resume. I’ll do my best to write some design-related articles as I get ideas.
I’m hoping to get the CCDA completed in the next few weeks. I’d like to get the CCDP done by February, but that might be a tad ambitious with my current workload.
Show Run Variations
Nov 28th
A recent thread on TechExams gave me the idea for a post on all the variations of the “show run” command. In this article I’ll go through the variations that I use the most, and some others that I don’t use much, but are pretty helpful.
Let’s take a look:
First we’ll look at all the options provided by IOS help:
EDGE#sh run ? all Configuration with defaults brief configuration without certificate data class-map Show class-map information control-plane Show Control-Plane information flow Global Flow configuration subcommands full full configuration interface Show interface configuration linenum Display line numbers in output map-class Show map class information policy-map Show policy-map information ssid Show Dot11 SSID information view View options vlan Show L2 VLAN information vrf Show VRF aware configuration | Output modifiers |
I’m sure everyone reading this has used good old “sh run” many times. What about the other options? I use “sh run interface” quite a bit:
EDGE#sh run int fa0/0 ... interface FastEthernet0/0 description OUTSIDE ip address xx.xx.xx.xx 255.255.255.248 ip access-group OUTSIDE_IN in no ip redirects no ip unreachables no ip proxy-arp ip accounting access-violations ip nbar protocol-discovery ip nat outside ip virtual-reassembly load-interval 30 duplex auto speed auto no cdp enable service-policy input QoS_IN service-policy output SHAPER end |
That and “sh run | section” are probably the variations I use most:
EDGE#sh run | sec ephone-dn ephone-dn 1 dual-line number 5001 no-reg primary label Colby name Colby ephone-dn 3 number 5003 no-reg primary label Laptop name Colby-Laptop ephone-dn 4 number 5004 no-reg primary name Wireless ephone-dn 5 number 5005 no-reg primary ephone-dn 6 number 5006 no-reg primary name Katie ephone-dn 11 dual-line number 555-555-5555 label 555-555-5555 name Colby |
That one is perfect for times when you are looking for specific parts of the config, without having to wade through everything.
A new one I just learned from Networking-Forum:
EDGE#sh run Building configuration... ! version 12.4 service timestamps debug datetime msec service timestamps log datetime msec service password-encryption ! /ospf <--- I typed this filtering... router ospf 200 router-id 192.168.254.254 log-adjacency-changes network 192.168.5.0 0.0.0.255 area 1 network 192.168.13.0 0.0.0.3 area 0 network 192.168.254.254 0.0.0.0 area 0 |
Policy-Based Routing Tutorial
Nov 18th
A friend asked me how to implement Policy-Based Routing (PBR) yesterday, after explaining it to him I thought it’d be nice to write a quick tutorial on here. PBR allows you to change a packet’s path based on different criteria. In this post I will use my friend’s scenario. We have a business with two internet connections, the powers that be have decided to use ISP B for all outbound SMTP traffic. Here’s our topology:
Let’s go through the config:
R1
hostname R1 ! ip access-list ext MATCH_SMTP 10 permit tcp 192.168.1.0 0.0.0.255 any eq 25 20 deny ip any any ! route-map SMTP_ISPB permit 10 match ip address MATCH_SMTP set ip next-hop 67.92.18.1 ! interface fa0/1 ip add 192.168.1.1 255.255.255.0 ip policy route-map SMTP_ISPB |
First we create our ACL that matches outgoing SMTP traffic, then we match the ACL in a route-map. After we match the traffic, we enter our action statement, “set ip next hop”. This route-map changes the next hope of all outgoing SMTP traffic. Finally we configure it on the LAN interface.
Free Cisco Lab
Nov 14th
Strech, the owner of PacketLife is now offering lab time for free. From his site:
Lab gear is broken into multiple “device blocks” to allow for multiple users to use independent portions of the lab simultaneously. Users can reserve one, several, or all of these blocks at once (however, a user may only have one unexpired reservation at any given time).
Block A
* 1x Cisco 2811 (with 2x WIC-2T)
* 2x Cisco 1841 (with 1x WIC-2T)
* 1x Cisco Catalyst 3550-24
* 1x Cisco Catalyst 3550-24 (with Inline Power)
* 1x Cisco ASA 5505
Block B
* 1x Cisco 2811 (with 2x WIC-2T)
* 2x Cisco 1841 (with 1x WIC-2T)
* 1x Cisco Catalyst 3550-24
* 1x Cisco Catalyst 3550-24 (with Inline Power)
BGP Backdoor Lab
Nov 12th
In this article we’ll be going over the BGP Backdoor feature. This is used in cases where two systems are connected via an IGP, but also receiving routes to the same system through BGP. I stumbled across this feature while checking out one of the labs on Darren’s Blog. The only way I could think of to complete one of his criteria was changing the Administrative Distance of either BGP or the IGP. That is essentially what this feature does, but on a route-by-route basis instead of changing the AD of an entire protocol. I asked Darren if that was the only solution and he pointed me to “BGP Backdoor”. As usual, I will be including my Dynagen/GNS3 .net file at the end of this post. Here is our topology:
Let’s go through the config:
R1
hostname R1 ! interface Serial0/0 ip address 10.1.1.1 255.255.255.0 ! interface Serial0/1 ip address 10.1.3.1 255.255.255.0 ! router bgp 65000 no synchronization bgp log-neighbor-changes neighbor 10.1.1.2 remote-as 65525 neighbor 10.1.3.2 remote-as 65535 no auto-summary |
New Dynamips Server
Nov 7th
Dell was running a deal on the PowerEdge T110 a couple weeks ago, so I decided to grab one as an upgrade to the T100 I was currently using for Dynamips on ESX.
Server specs:
X3430 Xeon Processor, 2.4 GHz 8M Cache
4GB DDR3 1333 RAM
500GB HDD
The T110 doesn’t support ESX (yet?), so I just did a straight install of Ubuntu 9.10. This thing is a beast, I brought up the completed MPLS and BGP lab I posted awhile back. Running at full steam it’s only using ~25% of the CPU. I’m pretty excited. This should be able to handle anything I can throw at it. Now I just need to find some more CCIE labs…
Update: ESXi is now supported on the T110 as of the ESXi4 U1 release.
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