Compare_Routerid [Disable | Enable] | Med_Confed [Disable | Enable] | Med_Missing_As_Worst - D-Link xStack DGS-3620 Reference Manual

xStack® DGS-3620 Series Layer 3 Managed Stackable Gigabit Switch CLI Reference Guide
DGS-3620-28PC:admin#
Command: config bgp timer holdtime 360 keepalive 120
Success.
DGS-3620-28PC:admin#
12-16 config bgp
Description
This command is used to configure the BGP best path selection related setting. MED is a metric
assigned to tell the external router how to choose a route. By default, MED is used to determine
the route that is advertised by the same AS.
The BGP deterministic med command can be configured to enforce a deterministic comparison of
the MED values between all the paths received from within the same Autonomous System
Default local preference:
By default, a BGP router will send the default local preference with the routes. It can be overwritten
if the local preference is set by the route map. For the received route, the local preference received
with the route will be used in the best path selection. This local preference will be overwrite if the
local preference is ingress set by the route map.
For the local routes, the default local preference will be used for them in the best path selection
Best path selection process:
The following is the steps that the BGP will use to select the best path among BGP routes:
1. Prefer the path that has the largest weight.
2. If the routes have the same weight, use the route with the highest local preference.
3. If the routes have the same local preference, prefer the route that was originated by BGP
on this router. Originated from network command > from redistribute command> from
aggregate command.
4. If no route was originated, prefer the route with the shortest AS path.
5. If all paths are of the same AS length, prefer the route with lowest origin code (IGP < EGP
< INCOMPLETE).
6. If the origin codes are the same, prefer the path with the lowest Multi Exit Discriminator.
7. If the MEDs are the same, prefer external paths over internal paths. EBGP
>Confederation>IBGP.
8. Prefer the path through the closest IGP neighbor.
9. Prefer the path that was received first (the oldest one).
10. Prefer the path with the lowest BGP Router ID.
11. Prefer to the routes advertised by the BGP speaker with a lower BGP identifier value.
12. Prefer to the routes advertised by the BGP speaker with lower peer address.
Format
config bgp {always_compare_med [disable | enable] | deterministic_med [disable | enable] |
default_local_preference <uint 0-4294967295> | bestpath {as_path_ignore [disable | enable]
| compare_routerid [disable | enable] | med_confed [disable | enable] |
med_missing_as_worst [disable | enable] | compare_confed_aspath [disable | enable]}(1)}(1)
config bgp timer holdtime 360 keepalive 120
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