Hello all, I have got an issue with GRE encapsulation, need some help. VPP creates broken tunnel, no actial connectivity. Both stable/1804 and master, Ubuntu Xenial, gcc 5.4.0
Steps to reproduce: 1. Create and configure veth pair ip link add name veth0 type veth peer name vpp0 ip link set dev vpp0 up ip link set dev veth0 up ip addr add 172.16.0.1/24 dev veth0 2. Run VPP and configure a tunnel DBGvpp# sh vervpp v18.10-rc0~434-gb4603a7 built by kahzeemin on kahzeemin-nix at Wed Sep 19 10:50:56 MSK 2018
DBGvpp# create host name vpp0 host-vpp0 DBGvpp# set int state host-vpp0 up DBGvpp# set int ip addr host-vpp0 172.16.0.2/24 DBGvpp# create gre tun src 172.16.0.2 dst 172.16.0.1 gre0 DBGvpp# ip route add 2001:db8::1/128 via gre0 DBGvpp# set int state gre0 up DBGvpp# enable ip6 int gre0 DBGvpp# sh ip6 fib 2001:db8::1/128ipv6-VRF:0, fib_index:0, flow hash:[src dst sport dport proto ] locks:[src:plugin-hi:1, src:default-route:1, ]
2001:db8::1/128 fib:0 index:12 locks:2 src:CLI refs:1 entry-flags:attached, src-flags:added,contributing,active, path-list:[14] locks:2 flags:shared, uPRF-list:15 len:1 itfs:[2, ]path:[14] pl-index:14 ip6 weight=1 pref=0 attached-nexthop: oper-flags:resolved, cfg-flags:attached,
2001:db8::1 gre0 (p2p)[@0]: ipv6 via :: gre0: mtu:9000 4500000000000000fe2f64abac100002ac100001000086dd
stacked-on:[@3]: ipv6 via 172.16.0.1 host-vpp0: mtu:9000 aae5c055aecc02fe6575de3586dd
forwarding: unicast-ip6-chain [@0]: dpo-load-balance: [proto:ip6 index:14 buckets:1 uRPF:15 to:[0:0]][0] [@6]: ipv6 via :: gre0: mtu:9000 4500000000000000fe2f64abac100002ac100001000086dd
stacked-on:[@3]: ipv6 via 172.16.0.1 host-vpp0: mtu:9000 aae5c055aecc02fe6575de3586dd
Please note this 'stacked-on: ipv6 via 172.16.0.1' leading to icmp6 neighbor discovery and no actual connectivity through the tunnel.
It looks like the problem is hardcoded next_hop_proto = DPO_PROTO_IP6 in add_del_route_t_handler invocation from ip6_add_del_route_t_handler (src/vnet/ip/ip_api.c:1091) and similar which is not necesseraly true about gre tunnels.
create host name vpp0 set int state host-vpp0 up set int ip addr host-vpp0 172.16.0.2/24 create gre tun src 172.16.0.2 dst 172.16.0.1 ip route add 2001:db8::1/128 via gre0 set int state gre0 up enable ip6 int gre0 sh ip6 fib 2001:db8::1/128
gre.sh
Description: application/shellscript
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