BGP: /32 network cannot be advertised unless "no bgp network import-check" is present
Hi, I've configured a dummy interface (in Linux) with IP Address 1.1.1.1/32 and advertising it in BGP. However, this network is not getting advertised unless I also give "no bgp network import-check" command. Please see below for more details and advise what could be going wrong or I'm missing some other configuration. (Same is true with IPv6 address with /128 prefix - this also cannot be advertised unless no import-check is given even though the address present in IPv6 routing table) Thanks Amol Current configuration: ! frr version 7.4 frr defaults traditional hostname FRR log syslog ! router bgp 1 no bgp ebgp-requires-policy neighbor 10.10.10.2 remote-as 2 ! address-family ipv4 unicast network 1.1.1.1/32 exit-address-family ! line vty ! end ==== FRR(config-router)# do show ip route Codes: K - kernel route, C - connected, S - static, R - RIP, O - OSPF, I - IS-IS, B - BGP, E - EIGRP, N - NHRP, T - Table, v - VNC, V - VNC-Direct, A - Babel, D - SHARP, F - PBR, f - OpenFabric, > - selected route, * - FIB route, q - queued route, r - rejected route K * 1.1.1.1/32 [0/10] is directly connected, loop0, 00:54:33 C>* 1.1.1.1/32 is directly connected, loop0, 00:54:33 === [ As you can see "*>" is missing before 1.1.1.1/32. However, If I give "no bgp network import-check" then *> comes here and network is advertised to neighbor] FRR(config-router)# do show bgp ipv4 unicast BGP table version is 2, local router ID is 172.17.1.106, vrf id 0 Default local pref 100, local AS 64512 Status codes: s suppressed, d damped, h history, * valid, > best, = multipath, i internal, r RIB-failure, S Stale, R Removed Nexthop codes: @NNN nexthop's vrf id, < announce-nh-self Origin codes: i - IGP, e - EGP, ? - incomplete Network Next Hop Metric LocPrf Weight Path 1.1.1.1/32 0.0.0.0 0 32768 i Displayed 1 routes and 1 total paths === root@FRR:/# ip addr show loop0 6: loop0: <BROADCAST,NOARP,UP,LOWER_UP> mtu 1500 qdisc noqueue state UNKNOWN group default qlen 1000 link/ether 52:db:5f:99:52:d4 brd ff:ff:ff:ff:ff:ff inet 1.1.1.1/32 brd 255.255.255.255 scope global loop0 valid_lft forever preferred_lft forever inet6 fe80::50db:5fff:fe99:52d4/64 scope link valid_lft forever preferred_lft forever ===
Amol - Please check and see if this commit fixes your issue: commit e8442016a84d27c22ec1d9c8915ff7192277f680 (origin/pr/7182, donald/bgp_static_32s, bgp_static_32s) Author: Donald Sharp <sharpd@nvidia.com> Date: Fri Sep 25 09:45:24 2020 -0400 bgpd: Allow bgp static routes to use /32's If you are including a network statement of a /32 then the current bgp martian checks will match the /32 together. Problem: ! router bgp 3235 neighbor 192.168.161.2 remote-as external neighbor 192.168.161.131 remote-as external ! address-family ipv4 unicast network 10.10.3.11/32 network 192.168.161.0/24 no neighbor 192.168.161.2 activate neighbor 192.168.161.2 route-map BLUE in exit-address-family ! eva# show bgp ipv4 uni BGP table version is 1, local router ID is 10.10.3.11, vrf id 0 Default local pref 100, local AS 3235 Status codes: s suppressed, d damped, h history, * valid, > best, = multipath, i internal, r RIB-failure, S Stale, R Removed Nexthop codes: @NNN nexthop's vrf id, < announce-nh-self Origin codes: i - IGP, e - EGP, ? - incomplete Network Next Hop Metric LocPrf Weight Path 10.10.3.11/32 0.0.0.0(eva) 0 32768 i *> 192.168.161.0/24 0.0.0.0(eva) 0 32768 i Displayed 2 routes and 2 total paths eva# show bgp import-check-table Current BGP import check cache: 192.168.161.0 valid [IGP metric 0], #paths 1 if enp39s0 Last update: Fri Sep 25 08:00:42 2020 10.10.3.11 valid [IGP metric 0], #paths 1 if lo Last update: Fri Sep 25 08:00:42 2020 eva# show bgp ipv4 uni summ BGP router identifier 10.10.3.11, local AS number 3235 vrf-id 0 BGP table version 1 RIB entries 3, using 576 bytes of memory Peers 1, using 21 KiB of memory Neighbor V AS MsgRcvd MsgSent TblVer InQ OutQ Up/Down State/PfxRcd PfxSnt janelle(192.168.161.131) 4 60000 69 70 0 0 0 00:03:21 0 1 Total number of neighbors 1 When we are deciding that a nexthop is valid there is not much point in checking that a static route has a martian nexthop or not, since we self derived it already. Signed-off-by: Donald Sharp <sharpd@nvidia.com> donald On Mon, Sep 28, 2020 at 6:46 AM Amol Lad <Amol.Lad@4rf.com> wrote:
Hi,
I've configured a dummy interface (in Linux) with IP Address 1.1.1.1/32 and advertising it in BGP. However, this network is not getting advertised unless I also give "no bgp network import-check" command. Please see below for more details and advise what could be going wrong or I'm missing some other configuration.
(Same is true with IPv6 address with /128 prefix - this also cannot be advertised unless no import-check is given even though the address present in IPv6 routing table)
Thanks Amol
Current configuration: ! frr version 7.4 frr defaults traditional hostname FRR log syslog ! router bgp 1 no bgp ebgp-requires-policy neighbor 10.10.10.2 remote-as 2 ! address-family ipv4 unicast network 1.1.1.1/32 exit-address-family ! line vty ! end
====
FRR(config-router)# do show ip route Codes: K - kernel route, C - connected, S - static, R - RIP, O - OSPF, I - IS-IS, B - BGP, E - EIGRP, N - NHRP, T - Table, v - VNC, V - VNC-Direct, A - Babel, D - SHARP, F - PBR, f - OpenFabric, > - selected route, * - FIB route, q - queued route, r - rejected route
K * 1.1.1.1/32 [0/10] is directly connected, loop0, 00:54:33 C>* 1.1.1.1/32 is directly connected, loop0, 00:54:33
===
[ As you can see "*>" is missing before 1.1.1.1/32. However, If I give "no bgp network import-check" then *> comes here and network is advertised to neighbor]
FRR(config-router)# do show bgp ipv4 unicast BGP table version is 2, local router ID is 172.17.1.106, vrf id 0 Default local pref 100, local AS 64512 Status codes: s suppressed, d damped, h history, * valid, > best, = multipath, i internal, r RIB-failure, S Stale, R Removed Nexthop codes: @NNN nexthop's vrf id, < announce-nh-self Origin codes: i - IGP, e - EGP, ? - incomplete
Network Next Hop Metric LocPrf Weight Path 1.1.1.1/32 0.0.0.0 0 32768 i
Displayed 1 routes and 1 total paths
===
root@FRR:/# ip addr show loop0 6: loop0: <BROADCAST,NOARP,UP,LOWER_UP> mtu 1500 qdisc noqueue state UNKNOWN group default qlen 1000 link/ether 52:db:5f:99:52:d4 brd ff:ff:ff:ff:ff:ff inet 1.1.1.1/32 brd 255.255.255.255 scope global loop0 valid_lft forever preferred_lft forever inet6 fe80::50db:5fff:fe99:52d4/64 scope link valid_lft forever preferred_lft forever
===
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Thanks Donald, your patch fixes the issue (both ipv4 and ipv6). -----Original Message----- From: Donald Sharp <sharpd@cumulusnetworks.com> Sent: Monday, 28 September 2020 5:13 PM To: Amol Lad <Amol.Lad@4rf.com> Cc: frog@lists.frrouting.org Subject: Re: [FROG] BGP: /32 network cannot be advertised unless "no bgp network import-check" is present Amol - Please check and see if this commit fixes your issue: commit e8442016a84d27c22ec1d9c8915ff7192277f680 (origin/pr/7182, donald/bgp_static_32s, bgp_static_32s) Author: Donald Sharp <sharpd@nvidia.com> Date: Fri Sep 25 09:45:24 2020 -0400 bgpd: Allow bgp static routes to use /32's If you are including a network statement of a /32 then the current bgp martian checks will match the /32 together. Problem: ! router bgp 3235 neighbor 192.168.161.2 remote-as external neighbor 192.168.161.131 remote-as external ! address-family ipv4 unicast network 10.10.3.11/32 network 192.168.161.0/24 no neighbor 192.168.161.2 activate neighbor 192.168.161.2 route-map BLUE in exit-address-family ! eva# show bgp ipv4 uni BGP table version is 1, local router ID is 10.10.3.11, vrf id 0 Default local pref 100, local AS 3235 Status codes: s suppressed, d damped, h history, * valid, > best, = multipath, i internal, r RIB-failure, S Stale, R Removed Nexthop codes: @NNN nexthop's vrf id, < announce-nh-self Origin codes: i - IGP, e - EGP, ? - incomplete Network Next Hop Metric LocPrf Weight Path 10.10.3.11/32 0.0.0.0(eva) 0 32768 i *> 192.168.161.0/24 0.0.0.0(eva) 0 32768 i Displayed 2 routes and 2 total paths eva# show bgp import-check-table Current BGP import check cache: 192.168.161.0 valid [IGP metric 0], #paths 1 if enp39s0 Last update: Fri Sep 25 08:00:42 2020 10.10.3.11 valid [IGP metric 0], #paths 1 if lo Last update: Fri Sep 25 08:00:42 2020 eva# show bgp ipv4 uni summ BGP router identifier 10.10.3.11, local AS number 3235 vrf-id 0 BGP table version 1 RIB entries 3, using 576 bytes of memory Peers 1, using 21 KiB of memory Neighbor V AS MsgRcvd MsgSent TblVer InQ OutQ Up/Down State/PfxRcd PfxSnt janelle(192.168.161.131) 4 60000 69 70 0 0 0 00:03:21 0 1 Total number of neighbors 1 When we are deciding that a nexthop is valid there is not much point in checking that a static route has a martian nexthop or not, since we self derived it already. Signed-off-by: Donald Sharp <sharpd@nvidia.com> donald On Mon, Sep 28, 2020 at 6:46 AM Amol Lad <Amol.Lad@4rf.com> wrote:
Hi,
I've configured a dummy interface (in Linux) with IP Address 1.1.1.1/32 and advertising it in BGP. However, this network is not getting advertised unless I also give "no bgp network import-check" command. Please see below for more details and advise what could be going wrong or I'm missing some other configuration.
(Same is true with IPv6 address with /128 prefix - this also cannot be advertised unless no import-check is given even though the address present in IPv6 routing table)
Thanks Amol
Current configuration: ! frr version 7.4 frr defaults traditional hostname FRR log syslog ! router bgp 1 no bgp ebgp-requires-policy neighbor 10.10.10.2 remote-as 2 ! address-family ipv4 unicast network 1.1.1.1/32 exit-address-family ! line vty ! end
====
FRR(config-router)# do show ip route Codes: K - kernel route, C - connected, S - static, R - RIP, O - OSPF, I - IS-IS, B - BGP, E - EIGRP, N - NHRP, T - Table, v - VNC, V - VNC-Direct, A - Babel, D - SHARP, F - PBR, f - OpenFabric, > - selected route, * - FIB route, q - queued route, r - rejected route
K * 1.1.1.1/32 [0/10] is directly connected, loop0, 00:54:33 C>* 1.1.1.1/32 is directly connected, loop0, 00:54:33
===
[ As you can see "*>" is missing before 1.1.1.1/32. However, If I give "no bgp network import-check" then *> comes here and network is advertised to neighbor]
FRR(config-router)# do show bgp ipv4 unicast BGP table version is 2, local router ID is 172.17.1.106, vrf id 0 Default local pref 100, local AS 64512 Status codes: s suppressed, d damped, h history, * valid, > best, = multipath, i internal, r RIB-failure, S Stale, R Removed Nexthop codes: @NNN nexthop's vrf id, < announce-nh-self Origin codes: i - IGP, e - EGP, ? - incomplete
Network Next Hop Metric LocPrf Weight Path 1.1.1.1/32 0.0.0.0 0 32768 i
Displayed 1 routes and 1 total paths
===
root@FRR:/# ip addr show loop0 6: loop0: <BROADCAST,NOARP,UP,LOWER_UP> mtu 1500 qdisc noqueue state UNKNOWN group default qlen 1000 link/ether 52:db:5f:99:52:d4 brd ff:ff:ff:ff:ff:ff inet 1.1.1.1/32 brd 255.255.255.255 scope global loop0 valid_lft forever preferred_lft forever inet6 fe80::50db:5fff:fe99:52d4/64 scope link valid_lft forever preferred_lft forever
===
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