Multilink & Virtual Template

[snarayanaraju]

Dear Experts & Friends

I am not able to figure out the difference between the usage of

Interface Multilink

and

multilink virtual-template

interface virtual-template

I know that the main advantage of both the tools is fragmentation. I tried it in Lab environment and found that both does the same job without any difference. I read in a blogs that virtual-template is generally used in ISP environments and dialer interfaces, further i am not getting the clues

Can you help me by explaning in which scenario to use Interface Multilink & interface virtual-template.

In generally use virtual-template in Frame relay scenarios where ppp authentication is required between FR interface. That much i know

Thanks in advance

sairam

[Edison Ortiz]

Interface Multilink are used when bundling ATM, PPP over Frame Relay or PPP serial interfaces.

Interface Virtual Template are used when bundling other WAN media such as ISDN which requires a logical dialer interface.

Keep in mind, a multilink group interface configuration will override a global multilink virtual template configured with the multilink virtual template command.

For more information, please refer to the documentation:

http://www.cisco.com/en/US/docs/ios/dial/configuration/guide/dia_media-ind_multi_ppp_ps6350_TSD_Products_Configuration_Guide_Chapter.html#wp1054168

Regards

Edison

[snarayanaraju]

Thanks Edison,

I remember I configured PPP Multilink  in ISDN and it was working perfectly. You may be perfectly correct. But i want to know is there any

1. Advantage of one over the other

2. What is the impact if i attempt to configure Interface Multilink on ISDN instead of Virtual Template

thanks

sairam

[Edison Ortiz · Accepted solution]

Interface Virtual-Templates are intended for dynamic access, in other words - dial-in and dial-out features from/to the router.

It is also use on PPP over Frame-Relay configurations as the command frame-relay interface-dlci xx ppp calls for a virtual-template to clone from, not a multilink interface. You can still use the multilink interface along with the virtual-template by binding the multilink with same ppp multilink group.

Another benefit of using a Virtual-Template that when the Virtual-Access is not in use, those resources are freed up by the router.

While, if you use Interface Multilink, those resources will be allocated permanently until you delete the interface from the config.

In terms of usability, they both offer the same kind of services and features under the logical interfaces.

All commands applied under the Interface Virtual-Template are valid under the Interface Multilink.

Regards

Edison