Lab Notes - Misc

Today I will be adding a little to my blog... I come across so many good things and have mounds of notes but nothing searchable! So I figured I would start to document and should any of this help anyone than great!

IP is a routed protocol. A routed protocol is a packet that carries data. It is different from a routing protocol in that the latter updates routers to let them know which path a packet should traverse.

If you are ever asked to configure a DHCP pool on the lab, make sure you look to see if there are any next hop redundancy protocols as this will dictate your Default Gateway unless otherwise noted on the lab.

When you configure Frame-Relay and are using FR map statements, you only need one per interface.

For Example:

interface Serial 0/1/0
encapsulation frame-relay
frame-relay map ip x.x.x.x 101 broadcast
frame-relay map ip x.x.x.x 102

Once there is a broadcast, then you are all set.

If you are configuring frame-relay and are able to use inverse arp, all you need to do go under the interface wether its Physical or sub interface and use the:

frame-relay interface DLCI XXX command and you are good to go.

VTP Pruning

Global Config Mode: vtp pruning

You can also go under an interface that is trunking and add / remove VLANs but remember this can only be done when the switch is a server.

To mitigate and enforce the ROOT switch placement, Cisco recommends:

intf# spanning-tree guard root

CDP ( Cisco Discovery Protocol )

Can show CDP neighbors but can also detect: Duplex Mismatches / Native VLAN Mismatches / VTP Domain Mismatches.
_______

NTP:

R1 is the NTP master, R2 is getting it's time from R1 and SW2 is getting its time from R2 and using authentication. <Relevant configuration below>

SW2#
access-list 17 permit 160.60.26.2
!
ntp authentication-key 1 md5 1306141B0E 7
ntp authenticate
ntp trusted-key 1
ntp access-group peer 17
ntp peer 160.60.26.2 key 1

R2#
ntp authentication-key 1 md5 0508050624 7
ntp server 160.60.123.1
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If using a Hub and Spoke topology and Multicast Sparse Mode, you can use "NBMA mode" to resolve the issue of sending out MC in which MC traffic was received.