[Contents]
[Prev]
[Next]
[Index]
[Report an Error]
Example: Rewriting MPLS and IPv4 Packet Headers
On a M320 and T-series platform, configure rewrite
tables and apply them in various ways to achieve the following results:
- For interface so-3/1/0, the three EXP rewrite
tables are applied to packets, depending on the protocol of the payload:
- IPv4 packets (VPN) that enter the LSPs on interface so-3/1/0 are initialized with values from rewrite table exp-inet-table. An identical 3-bit value is written into the
IP precedence and MPLS EXP bit fields.
- IPv4 packets (non-VPN) that enter the LSPs on interface so-3/1/0 are initialized with values from rewrite table rule-non-vpn. An identical 3-bit value is written into the IP
precedence and MPLS EXP bit fields.
- Non-IPv4 packets that enter the LSPs on interface so-3/1/0 are initialized with values from rewrite table rule1, and written into the MPLS EXP header field only. The
statement exp rule1 has the same result as exp rule1
protocol mpls.
- For interface so-3/1/0, IPv4 packets transmitted
over a non-LSP layer are initialized with values from IP precedence
rewrite table rule2.
- For interface so-3/1/1, IPv4 packets that enter
the LSPs are initialized with values from EXP rewrite table exp-inet-table. An identical 3-bit value is written into the IP precedence and
MPLS EXP bit fields.
- For interface so-3/1/1, MPLS packets other than
IPv4 Layer 3 types are also initialized with values from table exp-inet-table. For VPN MPLS packets with IPv4 payloads, the
CoS value is written to MPLS and IPv4 headers. For VPN MPLS packets
without IPv4 payloads, the CoS value is written to MPLS headers only.
- [edit class-of-service]
- rewrite-rules {
-
- exp exp-inet-table {
-
- forwarding-class best-effort {
- loss-priority low code-point 000;
- loss-priority high code-point 001;
- }
-
- forwarding-class assured-forwarding {
- loss-priority low code-point 010;
- loss-priority high code-point 011;
- }
-
- forwarding-class expedited-forwarding {
- loss-priority low code-point 111;
- loss-priority high code-point 110;
- }
-
- forwarding-class network-control {
- loss-priority low code-point 100;
- loss-priority high code-point 101;
- }
- }
-
- exp rule1 {
- ...
- }
-
- inet-precedence rule2 {
- ...
- }
- }
- exp rule_non_vpn {
- ...
- }
-
- interfaces {
-
- so-3/1/0 {
-
- unit 0 {
-
- rewrite-rules {
- exp rule1;
- inet-precedence rule2;
- exp exp-inet-table protocol mpls-inet-both; # For all VPN
traffic.
- exp rule_non_vpn protocol mpls-inet-both-non-vpn; # For
all non-VPN
# traffic.
- }
- }
- }
-
- so-3/1/1 {
-
- unit 0 {
-
- rewrite-rules {
- exp exp-inet-table protocol [mpls mpls-inet-both];
- }
- }
- }
- }
[Contents]
[Prev]
[Next]
[Index]
[Report an Error]
