When a priority decision is encountered, the priority number is used to judge which one is the best. But not all the priority comparision work as we thought, for some protocols the higher of the priority number is, the lower priority is. In this post, we summarized the relationship of commonly used priority number and priority.
| the larger number is, the higher priority is | default priority number | range |
stp priority | false | 32768 | 0-61400 |
stp port priority | false | 128 | 0-240 |
OSPF dr-priority | true | 1 | 0-255 |
OSPFv3 dr-priority | true | 1 | 0-255 |
route preference | false | NA | 0-255 |
BGP prefer value(when comparing to choose route) | true | 0 | 0-65535 |
BGP local-preference(when comparing to choose route) | true | 100 | 0-4294967295 |
BGP MED(when comparing to choose route) | false | 0 | 0-4294967295 |
BGP router-id(when comparing to choose route) | false | NA | NA |
BGP peer id(when comparing to choose route) | false | NA | NA |
isis dis | true | 64 | 0-127 |
E-Trunk priority | false | 100 | 1-254 |
vrrp vrid priority | true | 100 | 1-254 |
PIM c-bsr priority | true | 0 | 0-255 |
PIM c-rp priority | true | 0 | 0-255 |
PIM dr-priority | true | 1 | 0-4294967295 |
PIM dr-priority(interface) | true | 1 | 0-4294967295 |
istack | true | 100 | 1-255 |
CSS | true | 100 | 1-255 |
