EoMPLS frame

Ethernet frame

EIGRP notes

• In Named mode per-interface commands are configured under af-interface. Beware of existing eigrp commands in interface configuration that can be misleading
• In Named mode wide metrics are used by default
• It's required to configure authentication mode, otherwise it's considered inactive
• Beware of white space in key-strings within key chains. It is considered a valid key-string character. Always use "show key chain" to verify.
• Uses multicast address 224.0.0.10 for the hello messages but you can configure it to use unicast
• Both routers need to be configured as unicast in order to form an "unicast" adjacency .
• Default route advertisement using a summary address should be avoided. By default it creates a summary route with admin distance 5 pointing to null and can lead to blackholes under certain circumstances
• A summary route is advertised with the lowest metric of it's component routes
• Default hello interval 5 sec. On low speed NBMA networks it's 60 sec. Default hold time 4 x hello interval. Both configured per interface.
• Using "eigrp stub" feature the "connected" and "summary" are default keywords included. 
• EIGRP by default uses up to 50% of configured interface bandwidth. If the bandwidth is configured too low, EIGRP starvation may occur. If you have available bandwidth but you  have intentionally configured a low bandwidth for other reasons, you can increase the interface bandwidth or set the percentage to a value >100%
• The command "distance XXX subnet wildcard ACL" changes the distance of the routes matched by the ACL AND and are learned from specific sources matched by the "subnet wildcard" values. It only affects EIGRP internal routes.
• For redistribution from another protocol to EIGRP you need to set the default metric or specify a metric at the redistribute command. No need to specify that for redistribution from static & connected routes and between EIGRP processes.
• Command "show ip eigrp events" very useful for troubleshooting. Displays ignored ppackets and so on.
• You can filter routes using maximum hop count. It defaults to 100 hops.

VTP notes

• In VTP v1 & v2 change mode to transparent to reset revision number
• Vlan state(Active/Suspended) is advertised by VTP. Shutting down a vlan is locally significant to the device the the command was applied
• A transparent switch forwards VTP packets only if they match it's own configured VTP domain
• DTP negotiation between two switches requires VTP domain name to match between switches
• If a switch doesn't receive a VTP pruning response on a port, as a fallback mechanism, it doesn't prune any vlan on that port. As a consequence it requests all vlans from it VTP neighbors, which actually cancels VTP pruning operation. This is true for edge ports too. As a solution either disable VTP on that port(VTPv3) or manually set allowed vlan list. 
• Don't use VTP pruning on a VTP domain that includes transparent switches. Transparent switches only forward VTP packets and don't take part in the negotiation, leading to traffic blackholes
• By default all standard vlans are included in the prune eligible list
• VTP domain name is case sensitive
• In transparent mode vlans are stored in running config
• In client/server mode vlans are stored in vlan database
• In VTPv3 you have to define a primary server in exec mode in order to be able to alter the vlan database
• In VTPv3 you need to disable VTP pruning in order to advertise the extended vlan range
• Useful debug command: debug sw-vlan vtp events

Ping several hosts taking target IPs from a text file

Consider a file containing target IPs, one ip per line

With the following line you can ping them sequentially

for ip in `sort -u file` ; do fping -q -a -t200 ${ip} ; done

Only the ones that reply will be displayed on your screen

7600 l2protocol forward vs ME3400 l2protocol-tunnel

ME3400

ME3400 is able to tunnel l2 protocols with the command "l2protocol-tunnel xxx"

Tunneled STP BPDUs have 01-00-0C-CD-CD-D0 as a destination mac-address

7600

On 7600 when using service instances on ES cards there is only one option, l2protocol forward.
As the name implies, the router does not alter the BPDUs. It just forwards them on the bridge domain bypassing the SP.

Tunneled STP BPDUs have 01-00-0C-CC-CC-CD as a destination mac-address

Following these different approaches, they can't interoperate in any easy way..

Creating a Private Key and Public Certificate

Use the following OpenSSL command to create your private key. The command creates a 1,024-bit RSA private key stored in the file private-key.pem.

openssl genrsa –out private-key.pem 1024

Use the following OpenSSL command to create your public certificate. Run the command from the same directory that you ran the previous command to generate your private key. You will be prompted to enter some basic information for inclusion in the certificate, such as your name. The command generates a public certificate stored in the file public-cert.pem.

openssl req –new –key private-key.pem –x509 –days 365 –out public-cert.pem

That's all

Source: http://goo.gl/Cd24F