Daily Archives: February 17, 2013

3.7.b Implement and troubleshoot IBGP and EBGP

3.7.b [i] EBGP, IBGP

bgp swaps it’s tcp source and destination port numbers… read this from brian mcgahan, and test it… watch the bouncing port 179… i’m source port 179, no i’m source port 179… no i’m destination port 179… no i am…

http://blog.ine.com/2008/02/06/understanding-bgp-port-numbers/

atrophy…

and what do you do about it… if you were like me, you did route or switch first for ccnp, then finished with tshoot… i did switch first, doesn’t matter… the fact is i spent 5-6 months on switch, then 5-6 months on route, then about 3 months on tshoot… some people might think that’s slow although i do not… like i always say, there is no rush…

and here is how i went about it although i do not recommend this approach… for the 5-6 months of switch, that’s all i did… likewise for route for 5-6 months, and then the 2-3 months of tshoot…  i immersed myself each time in each category… i took my time with tshoot unlike most because i enjoyed the consolidation… i read too often about people racing through tshoot and i wasn’t going to be that guy… i did wallace’s ocg, his videos, the net acad lab manual, built the cisco topo and had a great time with boson’s tshoot sim trainer, etc.

which leads to the point: atrophy, and the fight against it…

atrophy happens… it is unavoidable…

so what am i doing about it? like the theme of this place, i begin again but adjust the tools…

the first 500 pages of wendell’s ccie ocg is review, and that is good… i’ve been through the ccie quick review and that is mostly review except for qos, mpls and multicast… those last three i’m spreading out… i will pick them up as i go along in a constant state of deep dive review… in other words, no more immersion to exclusion…  which means anki’s, constant testing, back to doyle, going forward a little, then back again, then back farther, and always core rejuvenation, l2-3, igp’s and bgp, osi and rfc’s…

no more segmentation… my plan is to see this thing as a whole… i think a little bit of everything over time is better than a lot of one thing…

 

3.3.i Implement, optimize and troubleshoot manual and auto summarization with any routing protocol

don’t look at me, i didn’t make it up…

from http://www.cisco.com/en/US/docs/ios/12_1/iproute/command/reference/1rdospf.html#wp1017596

area range

To consolidate and summarize routes at an area boundary, use the area range command in router configuration mode.
The area range command is used only with area border routers (ABRs). It is used to consolidate or summarize routes for an area. The result is that a single summary route is advertised to other areas by the ABR. Routing information is condensed at area boundaries. External to the area, a single route is advertised for each address range. This behavior is called route summarization.

summary-address (OSPF)

Routes learned from other routing protocols can be summarized. The metric used to advertise the summary is the smallest metric of all the more specific routes. This command helps reduce the size of the routing table.

Using this command for OSPF causes an OSPF autonomous system boundary router (ASBR) to advertise one external route as an aggregate for all redistributed routes that are covered by the address. For OSPF, this command summarizes only routes from other routing protocols that are being redistributed into OSPF. Use the area range command for route summarization between OSPF areas.