Virtual-Template on PPP - FR

Rupesh Kashyap · ‎01-08-2009

Hi,

why we require Virtual-Template on PPP on Frame Relay.

Giuseppe Larosa · ‎01-08-2009

Hello Rupesh,

from FR configuration guide:

One PPP connection resides on one virtual access interface. This is internally created from a virtual template interface, which contains all necessary PPP and network protocol information and is shared by multiple virtual access interfaces. The virtual access interface is coexistent with the creation of the Frame Relay circuit when the corresponding DLCI is configured. Hardware compression and fancy queueing algorithms, such as weighted fair queueing, custom queueing, and priority queueing, are not applied to virtual access interfaces.

PPP over Frame Relay is only supported on IP. IP datagrams are transported over the PPP link using RFC 1973 compliant Frame Relay framing

see

http://www.cisco.com/en/US/docs/ios/12_1/wan/configuration/guide/wcdfrely.html#wp1002008

the PPP session uses a virtual dialup object, a virtual access, that is created dynamically and inherits its properties from a master virtual-template object

Hope to help

Giuseppe

Rupesh Kashyap · ‎01-08-2009

Hi,

I want to know that if we have frame-relay between three sites having EIGRP MD5 authentication. Then PPP Virtual Templete is mandatory or we can configure simple Frame-relay without ppp & virtual templete ?

Giuseppe Larosa · ‎01-09-2009

Hello Rupesh,

you can use directly the FR interfaces on each site.

I wouldn't use PPP over FR in your scenario

You can choice between:

two point-to-point logical links using

point-to-point subifs

or you can use point-to-multipoint subifs and a single ip subnet.

Be aware that in this case central site will need to disable EIGRP split-horizon in order to propagate routes from remote site1 to remote site2 and viceversa.

And you will need to use

frame-relay map ip remote dlci# broadcast

the broadcast option is needed

(this in case of multipoint)

You can use MD5 authentication with EIGRP but I would suggest to add it in a second time.

However, be aware that when you will add the MD5 configuration the EIGRP adjacencies will be reset.

I would suggest to use point-to-point logical links if IP addressing is not issue (if using RFC1918 private ip addressing)

Hope to help

Giuseppe