Table: Legacy link TE TLV support in TE-DB and BGP-LS lists the TE attributes that are advertised using the legacy link TE TLVs defined in RFC 5305 for IS-IS and in RFC 3630 for OSPF. These TE attributes are carried in BGP-LS in accordance with RFC 7752. These legacy TLVs are already supported in SR OS and in IS-IS, OSPF, and BGP-LS.
To support IPv6 TE, the IS-IS IPv6 TE attributes (IPv6 TE router ID and IPv6 SRLG TLV) are advertised in BGP-LS in accordance with RFC 7752. These attributes can now be advertised within the ASLA TLV in IS-IS as recommended in RFC 8919 and in BGP-LS as recommended in draft-ietf-idr-bgp-ls-app-specific-attr. In the latter case, BGP-LS uses the same TLV type defined in RFC 7752 but is included as a sub-TLV of the new BGP-LS ASLA TLV. The following table also lists the code points for IS-IS and BGP-LS TLVs.
| Link TE TLV description | IS-IS TLV type (RFC 5305) | OSPF TLV type (RFC 3630) | BGP-LS link NLRI link-attribute TLV type (RFC 7752) |
|---|---|---|---|
|
Administrative group (color) |
3 |
9 |
1088 |
|
Maximum link bandwidth |
9 |
6 |
1089 |
|
Maximum reservable link bandwidth |
10 |
7 |
1090 |
|
Unreserved bandwidth |
11 |
8 |
1091 |
|
TE Default Metric |
18 |
5 |
1092 |
|
SRLG |
138 (RFC 4205) |
16 (RFC 4203) |
1096 |
|
IPv6 SRLG TLV |
139 (RFC 6119) |
— |
1096 |
|
IPv6 TE Router ID |
140 (RFC 6119) |
— |
1029 |
|
Application Specific Link Attributes |
16 (RFC 8919) |
— |
1122 (provisional, as per draft-ietf-idr-bgp-ls-app-specific-attr) |
|
Application Specific SRLG TLV |
238 (RFC 8919) |
— |
1122 (provisional, as per draft-ietf-idr-bgp-ls-app-specific-attr) |
The following table lists the TE attributes that are received from a third-party router implementation in legacy TE TLVs, or in the ASLA TLV for the RSVP-TE or SR-TE applications that are added into the local SR OSTE-DB; these are also distributed by the BGP-LS originator. However, these TLVs are not originated by an SR OS router IGP implementation.
| Link TE TLV description | IS-IS TLV type (RFC 7810) | OSPF TLV type (RFC 7471) | BGP-LS link NLRI link-attribute TLV type (RFC 8571) |
|---|---|---|---|
|
Unidirectional Link Delay |
33 |
27 |
1114 |
|
Min/Max Unidirectional Link Delay |
34 |
28 |
1115 |
|
Unidirectional Delay Variation |
35 |
29 |
1116 |
|
Unidirectional Link Loss |
36 |
30 |
1117 |
|
Unidirectional Residual Bandwidth |
37 |
31 |
1118 |
|
Unidirectional Available Bandwidth |
38 |
32 |
1119 |
|
Unidirectional Utilized Bandwidth |
39 |
33 |
1120 |
Any other TE attribute received in a legacy TE TLV or in an Application Specific Link Attributes TLV is not added to the local router TE-DB and, therefore, is not distributed by the BGP-LS originator.