BGP peers,timers, authentication

BGP Globally Unique (public) AS# Range 1-64511

BGP Private AS# Range 64512 – 65535

router bgp (as can’t be previously used)

router bgp 650002

bgp router-id

neighbor remote-as 65002

then configure on the other


next router


router bgp 65002

bgp router-id

neighbor remote-as 65001

neighbor remote-as 65002



sh ip bgp sum



OSPF for IPv6

ipv6 router ospf 1



int f0/0

ipv6 ospf 1 area 0

int f1/0

ipv6 ospf 1 area 0


do the same thing pretty much on the other routers change router-id

sh ipv6 ospf inter bri



OSPF Path Preference

Path Preference

1 Intra-Area (O) – routes learned from the same area

2 Inter-area (O IA) – routes learned from a different area

3 External Type 1 (E1) – routes learned from outside OSPF marked as E1

4 External Type 2 (E2) – routes learend outside of OSPF marked as E2

5 NSSA Type 1 (N1) –  routes learned from a NSSA area marked as N1

6 NSSA Type 2 (N2) – routes learned from a NSSA area marked as N2

sh ip route ospf


router ospf path types.PNG

LSA Types


1 router lsa router link advertisements within an area

2 network lsa  dr link advertsiements within an area

3 summary lsa abr network advertisements between areas

4 summary abr network advertisements between areas

5 external lsa asbr edternal route advertsiements

6 multacast lsa multicast advertsiements

7 nssa external lsa nssa asbr external route advertsiemetns

8 external attribute lsa for bgp bgp advertsiements

9-11 opaque lsa for future use



OSPF Network Types

point to point

dynamic 10

no dr bdr



manual 30

no dr bdr



dynamic 10

dr bdr



manual 30

dr bdr


router types


internal routers conencted to the same area

backbone routers routers connected to area 0

area border router abr routers connected to multiple areas

autonomous systems border router asbr routers conencted to segmetns external to ospf



OSPF Authentication

int f0/0

ip ospf message-digest-key or authentication-key

ip ospf message-digest-key 1 md5 cisco

ip ospf authentication message-digest

int f1/0

ip ospf message-digest-key 1 md5 cisco

ip ospf authentication message-digest


router ospf 1

area 0 authentication message-digest




OSPF Review




router id

router ospf 1

(process id is 1)


passive-interface default

no passive-interfcace f0/0

no passive-interfcace f1/0

network area 0


sh ip ospf int  brief


make template copy paste with different router ids


sh ip ospf nei


EIGRP Path Preference and Load Balancing

Bandwidth and Delay

Metric Value – bandwidth, load, delay, reliability, mtu

default is bandwidth and delay


config t

ip route name default-route

show run | i  0.0.0

router eigrp

red static


sh ip eigrp topo

(all paths even if not showed in routing table)

Feasible successor is a path whos reported distance is less than the feasible distance and it is considered a backup route. Eigrp will keep up to six feasible successors in the topology table. Only the one with the best metric the successor is placed in the routing table.

Equal cost load balancing and unequal cost load balancing

EIGRP provides a mechanism to laod balance over unequal cost paths through varience command. Varience is a number 1 to 128 multiplied by the local bes tmetric then includes the routes with the lessor or equal metric. The default varience value is 1 which means equal-cost load balancing


router eigrp1

no passive-interface f1/1

router eigrp 1

no auto-summary

passive-itnerface default

no passive-interface f0/1

eigrp stub

sh ip eigrp nei




suppressing queries


without license advance routing, it could cause issues




ipv6 unicast-routing

ipv6 router eigrp 1

(define router id)

eigrp router-id


do that on the other devices too


show ipv6 eigrp inter


make template, copy paste