Cisco Router and Avaya Phone VPN example


ip local pool IPADDR_VPN_POOL x.x.x.x x.x.x.x
aaa new-model
aaa authentication login LETMEIN_GROUPx local
aaa authentication login userauthen local
aaa authorization network LETMEIN_GROUPx local
username AVAYAx1 password 0 xxxx1
username AVAYAx2 password 0 xxxx2
username AVAYAx3 password 0 xxxx3
username AVAYAx4 password 0 xxxx4
crypto isakmp policy 1
encr 3des
hash md5
authentication pre-share
group 2
crypto isakmp client configuration group LETMEIN_GROUPx
key $x$x$
crypto ipsec transform-set MYTSET_3DESx esp-3des esp-md5-hmac
crypto ipsec security-association lifetime seconds 86400
crypto dynamic-map dynmap2 20
set transform-set MYTSET
set pfs group2
crypto map clientmap client authentication list userauthen
crypto map clientmap isakmp authorization list groupauthor
crypto map clientmap client configuration address respond
interface XXX/XXX
ip address X.X.X.X X.X.X.X
crypto map clientmap

crypto map clientmap 20 ipsec-isakmp dynamic dynmap2


Mandatory, Supported, Disabled


The black and white from Cisco defines that the use of Data Rates options to specify the rates at which data can be transmitted between the access point and the client.

The data rates are available:

• 802.11a—6, 9, 12, 18, 24, 36, 48, and 54 Mbps

• 802.11b/g—1, 2, 5.5, 6, 9, 11, 12, 18, 24, 36, 48, or 54 Mbps

For each data rate, choose one of these options:

Mandatory—Clients must support this data rate in order to associate to an access point on the controller. Why force 11Mbps on an SSID, if not only to enforce better performance.

Supported—Any associated clients that support this data rate may communicate with the access point using that rate. However, the clients are not required to be able to use this rate in order to associate.

Disabled—The clients specify the data rates used for communication.

The notes say the clients must support and not operate at this rate and the supported option identifies a not required. I think I will attempt to test the overall enforcement and remove any ambiguity. I know this is one that I’ve always assumed what the options mean…

More to follow

Wireless Aerial Coverage


The following link was one I found when investigating the use of 1131AG access points. The positioning on a ceiling is certainly better qualified after reviewing this document.



Update the 000-default file with the following details below to add basic authentication.

<VirtualHost *:80>

ServerAdmin webmaster@localhost

DocumentRoot /var/www

<Directory />

Options FollowSymLinks

AllowOverride None

order deny,allow


<Directory /var/www/>

Options Indexes FollowSymLinks MultiViews

AllowOverride none

order allow,deny

allow from all


ScriptAlias /cgi-bin/ /usr/lib/cgi-bin/

        <Directory “/usr/lib/cgi-bin”>

                AuthType Basic

                AuthName “CVS REPO”

                AuthUserFile /etc/apache2/.htpasswd

                AllowOverride All

                Require valid-user


The command below will allow you to create a new user and it will lead you through adding a password for that user.

network@S-ABD-RANCID:$ sudo htpasswd -c .htpasswd myuser

Cisco ASA, IPSEC bypass options (bozo)


To permit ANY packets that come from an IPsec tunnel without checking any ACLs such as the OUTIDE_ACCESS_IN The following example enables IPsec traffic through the ASA without checking ACLs:

hostname(config)# sysopt connection permit-vpn

VTP (never use it) you need to know it


VLAN TRUNKING PROTOCOL is designed to ease administration  of a large number of switches. It manages addistions, deletions and renaming. You can only apply one VTP domain to a switch.

There are 3 versions of VTP and only two of those are actively used (V3 is CAT/OS). VTP is a method of synchronising the vlan databases of switches. The term domain is used to identify a cluster/group of switches. If the databases are to be shared then the domain name and any passwords set must match (not totally true, read below for more details).

VTP advertisements are based upon the revision number and are sent when a change is made or every 5 minutes. The advertisments are multicast frames.

A summary advertisment is sent out every 300 seconds and if a change occurs.

A subset advertisment after a configuration change. VLAN name, SAID value, type and MTU.

A request from client switch used to obtain up to date information.

Each change made to a vlan will increase the revision number. A switch will compare revision numbers when it receives an advertisement. A switch will overwrite its VTP database if the update from one of it’s peers is higher (potentially making an automatic change to the assigned vlan’s). The advertisement is forwarded onto any neighbours. If the switch receives a VTP advertisement with a lower revision it will reply with it’s advertisement to update it’s neighbour.

The roles are:

SERVER: This is the default and will allow the switch to create, delete and rename vlan’s.

CLIENT: Apparently clients cannot make changes. However, I have seen events where client switches have been able to pass on updates to server peers.

TRANSPARENT: Allows the creation, deletion and renaming vlan’s but all information remains local. This mode will forward VTP information to its peers.

The use of show vtp status identifies the version in use, the revision number and the number of vlans that are being passed around via VTP.

Q-in-Q VLAN tunnels


Q-in-Q allows already tagged frames across a network by tunnelling them inside a single vlan. The process adds a second 802.1Q tag to each frame. As the packets traverse the network the network the infrastructure see’s the outside tag and forwards based on that vlan. Q-in-Q tunnels are usually implemented by service providers to encapsulate a customers multiple vlans into a single vlan.

Eg: as a simple example

Customer vlans 1,2,3,4,5
Service provider vlan 100

Customer switch trunk vlans 1-5 —-> (service provider dot1q-tunnel vlan 100) ——> vlans 1-5

This is enabled with:

switchport mode dot1q-tunnel

The tunnel interfaces should be setup at either end of the overall link.