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| LDP Signaled LSP |
R1 Configuration
protocols {mpls {
interface all;
}
bgp {
group ibgp {
type internal;
local-address 1.1.1.1;
neighbor 2.2.2.2;
neighbor 3.3.3.3;
neighbor 4.4.4.4;
}
}
ospf {
area 0.0.0.1 {
stub;
interface em1.12;
interface em1.13;
interface lo0.1 {
passive;
}
}
}
ldp {
interface all;
}
}
routing-options {
autonomous-system 100;
}
Verifying OSPF Routes and Database
root@Olive# run show ospf database logical-system r1
OSPF database, Area 0.0.0.1
Type ID Adv Rtr Seq Age Opt Cksum Len
Router *1.1.1.1 1.1.1.1 0x8000000c 432 0x20 0x67b7 60
Router 2.2.2.2 2.2.2.2 0x80000007 438 0x20 0x5cd2 36
Router 3.3.3.3 3.3.3.3 0x80000007 434 0x20 0x3ee4 36
Network 192.168.12.2 2.2.2.2 0x80000003 438 0x20 0xa905 32
Network 192.168.13.3 3.3.3.3 0x80000003 434 0x20 0x980c 32
Summary 0.0.0.0 2.2.2.2 0x80000001 530 0x20 0xcf5d 28
Summary 0.0.0.0 3.3.3.3 0x80000001 534 0x20 0xb177 28
Summary 2.2.2.2 2.2.2.2 0x80000002 106 0x20 0xd21 28
Summary 2.2.2.2 3.3.3.3 0x80000003 433 0x20 0xf631 28
Summary 3.3.3.3 2.2.2.2 0x80000003 432 0x20 0xe641 28
Summary 3.3.3.3 3.3.3.3 0x80000003 118 0x20 0xbe66 28
Summary 4.4.4.4 2.2.2.2 0x80000002 432 0x20 0xba6a 28
Summary 4.4.4.4 3.3.3.3 0x80000002 433 0x20 0x9c84 28
Summary 192.168.23.0 2.2.2.2 0x80000008 438 0x20 0xb7f6 28
Summary 192.168.23.0 3.3.3.3 0x80000003 478 0x20 0xa30c 28
Summary 192.168.24.0 2.2.2.2 0x80000008 432 0x20 0xac01 28
Summary 192.168.24.0 3.3.3.3 0x80000003 433 0x20 0xa20b 28
Summary 192.168.34.0 2.2.2.2 0x80000003 432 0x20 0x5255 28
Summary 192.168.34.0 3.3.3.3 0x80000006 433 0x20 0x247d 28
Summary 192.168.45.0 2.2.2.2 0x80000002 432 0x20 0xdac2 28
Summary 192.168.45.0 3.3.3.3 0x80000002 433 0x20 0xbcdc 28
Summary 192.168.46.0 2.2.2.2 0x80000002 432 0x20 0xcfcc 28
Summary 192.168.46.0 3.3.3.3 0x80000002 433 0x20 0xb1e6 28
root@Olive# run ping 4.4.4.4 logical-system r1 rapid
PING 4.4.4.4 (4.4.4.4): 56 data bytes
!!!!!
--- 4.4.4.4 ping statistics ---
5 packets transmitted, 5 packets received, 0% packet loss
round-trip min/avg/max/stddev = 0.968/1.201/1.576/0.232 ms
root@Olive# run show ldp interface logical-system r1 detail
Interface Label space ID Nbr count Next hello
lo0.1 1.1.1.1:0 0 0
Hello interval: 15, Hold time: 45, Transport address: 1.1.1.1
em1.12 1.1.1.1:0 1 3
Hello interval: 5, Hold time: 15, Transport address: 1.1.1.1
em1.13 1.1.1.1:0 1 4
Hello interval: 5, Hold time: 15, Transport address: 1.1.1.1
root@Olive# run show ldp neighbor logical-system r1 detail
Address Interface Label space ID Hold time
192.168.12.2 em1.12 2.2.2.2:0 13
Transport address: 2.2.2.2, Configuration sequence: 1
Up for 00:10:20
192.168.13.3 em1.13 3.3.3.3:0 11
Transport address: 3.3.3.3, Configuration sequence: 1
Up for 00:10:20
Default ldp hello-interval 5s, hold time 15s, MPLS Router use loopback interfaces for LDP establish.
LDP protocol priority is 9, if the network use IGP and LDP together, because the LDP priority is
lower than any priority other IGP protocol [9], So it will select LDP routing protocol,
but the LDP is inseparable from the IGP path, that is why the LDP and IGP path is same.
See LDP routing table
root@Olive# run show route table inet.3 logical-system r1
inet.3: 3 destinations, 3 routes (3 active, 0 holddown, 0 hidden)
+ = Active Route, - = Last Active, * = Both
2.2.2.2/32 *[LDP/9] 00:13:39, metric 1
> to 192.168.12.2 via em1.12
3.3.3.3/32 *[LDP/9] 00:13:35, metric 1
> to 192.168.13.3 via em1.13
4.4.4.4/32 *[LDP/9] 00:13:35, metric 1
to 192.168.12.2 via em1.12, Push 299808
> to 192.168.13.3 via em1.13, Push 299792
To 2.2.2.2/32 use label POP, because r1-r2 is connected directly
To 4.4.4.4/32 use label PUSH, PUSH label 299808
To 4.4.4.4/32 use label PUSH, PUSH label 299808
When traffic reach R2 the label will be POP
root@Olive# run show route table mpls.0 logical-system r2 label 299792 mpls.0: 9 destinations, 9 routes (9 active, 0 holddown, 0 hidden)
+ = Active Route, - = Last Active, * = Both
299792 *[LDP/9] 00:16:00, metric 1
> to 192.168.12.1 via em2.12, Pop
299792(S=0) *[LDP/9] 00:16:00, metric 1
> to 192.168.12.1 via em2.12, Pop
root@Olive# run show route table mpls.0 logical-system r2 label 299808
mpls.0: 9 destinations, 9 routes (9 active, 0 holddown, 0 hidden)
+ = Active Route, - = Last Active, * = Both
299808 *[LDP/9] 00:16:46, metric 1
> to 192.168.24.4 via em2.24, Pop
299808(S=0) *[LDP/9] 00:16:46, metric 1
> to 192.168.24.4 via em2.24, Pop
LDP routing table only has other router’s loopback interface /32 route.
It use for reach the bgp protocol next-hop
It use for reach the bgp protocol next-hop
Traceroute BGP Route，It's use LDP path or not
root@Olive# run traceroute 5.5.5.5 logical-system r1traceroute to 5.5.5.5 (5.5.5.5), 30 hops max, 40 byte packets
1 192.168.12.2 (192.168.12.2) 0.951 ms 0.518 ms 0.355 ms
2 192.168.24.4 (192.168.24.4) 0.750 ms 0.886 ms 0.924 ms
3 5.5.5.5 (5.5.5.5) 1.334 ms 1.974 ms 2.987 ms
Strange, its not using LDP path, but directly through IGP path.
The reason is R1 learn bgp route 5.5.5.5/32’s next-hop is R5
root@Olive# run show route 5.5.5.5 extensive logical-system r1inet.0: 18 destinations, 18 routes (18 active, 0 holddown, 0 hidden)
5.5.5.5/32 (1 entry, 1 announced)
TSI:
KRT in-kernel 5.5.5.5/32 -> {indirect(131077)}
*BGP Preference: 170/-101
Next hop type: Indirect
Next-hop reference count: 3
Source: 4.4.4.4
Next hop type: Router, Next hop index: 131073
Next hop: 192.168.12.2 via em1.12, selected
Next hop: 192.168.13.3 via em1.13
Protocol next hop: 192.168.45.5
Indirect next hop: 8d4b0a8 131077
State:
root@Olive# show r4 policy-options policy-statement nhs
term 1 {
from {
protocol bgp;
neighbor [ 192.168.45.5 192.168.46.6 ];
}
then {
next-hop self;
}
}
root@Olive# show r4 protocols bgp group ibgp
type internal;
local-address 4.4.4.4;
export nhs;
neighbor 1.1.1.1;
neighbor 2.2.2.2;
neighbor 3.3.3.3;
check route table
root@Olive# run show route 5.5.5.5/32 logical-system r1 inet.0: 18 destinations, 18 routes (18 active, 0 holddown, 0 hidden)
+ = Active Route, - = Last Active, * = Both
5.5.5.5/32 *[BGP/170] 00:20:59, localpref 100, from 4.4.4.4
AS path: 200 I
> to 192.168.12.2 via em1.12, Push 299808
to 192.168.13.3 via em1.13, Push 299792
Now the route has MPLS label
root@Olive# run traceroute 5.5.5.5 logical-system r1 traceroute to 5.5.5.5 (5.5.5.5), 30 hops max, 40 byte packets
1 192.168.12.2 (192.168.12.2) 1.452 ms 0.889 ms 1.188 ms
MPLS Label=299808 CoS=0 TTL=1 S=1
2 192.168.24.4 (192.168.24.4) 0.972 ms 1.111 ms 1.105 ms
3 5.5.5.5 (5.5.5.5) 1.545 ms 1.425 ms 1.580 ms
