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BGP Med

Why is the med field sometimes blank. Can you give an example for when it's blank, and when it is = 0

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Anonymous
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Re: BGP Med

The MED is not a required attribute for BGP announcements. When the MED is not included in a BGP announcement the MED field will be blank. When it is included in the BGP announcement, the value to which it is set will appear in the BGP table.

By default, Cisco routers assume a MED of 0 for BGP announcements which do not contain a MED attribute. However, the IETF has changed their policy on announcements with a missing MED to require the routers assume a MED of infiniti for those announcements. To configure the router to follow this behavior, you need to use the BGP router command 'bgp bestpath med missing-as-worst'. Note that as with any change to the BGP path selection algorithm, this command should be applied uniformly within an AS.

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