[FS#595] odhcpd in relay mode floods network with NS packets

LEDE Bugs lede-bugs at lists.infradead.org
Sat Mar 4 17:35:25 PST 2017 

A new Flyspray task has been opened.  Details are below. 

User who did this - netprince (netprince) 

Attached to Project - LEDE Project
Summary - odhcpd in relay mode floods network with NS packets
Task Type - Bug Report
Category - Base system
Status - Unconfirmed
Assigned To - 
Operating System - All
Severity - Medium
Priority - Very Low
Reported Version - lede-17.01
Due in Version - Undecided
Due Date - Undecided
Details - 
 - Device problem occurs on (all are ar71xx devices)

2x NETGEAR WNDR3700
3x WD My Net N750
1x GL AR150

 - Software versions of LEDE release, packages, etc.

LEDE Reboot 17.01-SNAPSHOT r2993+234-ef5cb96

 - Steps to reproduce

I setup 6 routers, wan has a static IPv4, wan6 set to dhcpv6.  I use odhcpd in relay mode because our network does not do prefix delegation.  All routers have separate physical internal LAN networks, but they share the same physical external WAN/WAN6 network.  After approx 8-12 hours the symptoms occur.  If I stop odhcpd on all routers, the problem goes away.

When the problem occurs, ipv6 appears to work normally.  odchpd hogs the cpu, anywhere from 20%-35% constant.  Also logread reports many addresses are 'forgot' and 'learned'  (see below)


config dhcp 'lan'
        option interface 'lan'
        option start '100'
        option limit '99'
        option leasetime '12h'
        #option dhcpv6 'relay'
        option ndp 'relay'
        option ra 'relay'

config dhcp 'wan'
        option interface 'wan'
        option ignore '1'

config dhcp 'wan6'
        option interface 'wan'
        #option dhcpv6 'relay'
        option ndp 'relay'
        option ra 'relay'
        option master '1'

config odhcpd 'odhcpd'
        option maindhcp '0'
        option leasefile '/tmp/hosts/odhcpd'
        option leasetrigger '/usr/sbin/odhcpd-update'



Sample traffic from the WAN using 'tcpdump -i eth0 icmp6'

NOTE: my routers end in:

70b7
77a8
2c21
71fb
4e2e
652a

NOTE: It looks to me like my 5 remote routers seem to be repeating every request to this router.


20:22:31.174215 IP6 ----.----.----.----:e291:f5ff:fe00:70b7 > ff02::1:ff88:f822: ICMP6, neighbor solicitation, who has ----.----.----.----:a014:6ffb:6188:f822, length 32
20:22:31.175013 IP6 ----.----.----.----:290:a9ff:feac:2c21 > ff02::1:ff88:f822: ICMP6, neighbor solicitation, who has ----.----.----.----:a014:6ffb:6188:f822, length 32
20:22:31.267340 IP6 ----.----.----.----:c23f:eff:fe7c:77a8 > ff02::1:ff71:2d25: ICMP6, neighbor solicitation, who has ----.----.----.----:8c42:9741:e071:2d25, length 32
20:22:31.271541 IP6 ----.----.----.----:e695:6eff:fe40:652a > ff02::1:ff71:2d25: ICMP6, neighbor solicitation, who has ----.----.----.----:8c42:9741:e071:2d25, length 32
20:22:31.273514 IP6 ----.----.----.----:e291:f5ff:fe00:70b7 > ff02::1:ff78:6cf: ICMP6, neighbor solicitation, who has ----.----.----.----:bcc1:bb13:d978:6cf, length 32
20:22:31.276696 IP6 ----.----.----.----:290:a9ff:feac:2c21 > ff02::1:ff71:2d25: ICMP6, neighbor solicitation, who has ----.----.----.----:8c42:9741:e071:2d25, length 32
20:22:31.276805 IP6 ----.----.----.----:290:a9ff:feac:2c21 > ff02::1:ff9e:ae42: ICMP6, neighbor solicitation, who has ----.----.----.----:ecc6:8d71:969e:ae42, length 32
20:22:31.276845 IP6 ----.----.----.----:e291:f5ff:fe00:70b7 > ff02::1:ff9e:ae42: ICMP6, neighbor solicitation, who has ----.----.----.----:ecc6:8d71:969e:ae42, length 32
20:22:31.281947 IP6 ----.----.----.----:c24a:ff:fedd:4e2e > ff02::1:ff78:6cf: ICMP6, neighbor solicitation, who has ----.----.----.----:bcc1:bb13:d978:6cf, length 32
20:22:31.287344 IP6 ----.----.----.----:c23f:eff:fe7c:77a8 > ff02::1:ff78:6cf: ICMP6, neighbor solicitation, who has ----.----.----.----:bcc1:bb13:d978:6cf, length 32
20:22:31.289173 IP6 ----.----.----.----:c24a:ff:fedd:4e2e > ff02::1:ff9e:ae42: ICMP6, neighbor solicitation, who has ----.----.----.----:ecc6:8d71:969e:ae42, length 32
20:22:31.295130 IP6 ----.----.----.----:290:a9ff:feac:2c21 > ff02::1:ff78:6cf: ICMP6, neighbor solicitation, who has ----.----.----.----:bcc1:bb13:d978:6cf, length 32
20:22:31.297330 IP6 ----.----.----.----:c23f:eff:fe7c:77a8 > ff02::1:ff9e:ae42: ICMP6, neighbor solicitation, who has ----.----.----.----:ecc6:8d71:969e:ae42, length 32
20:22:31.309099 IP6 ----.----.----.----:c24a:ff:fedd:4e2e > ff02::1:ff76:1ec6: ICMP6, neighbor solicitation, who has ----.----.----.----:6c23:859:3176:1ec6, length 32
20:22:31.312935 IP6 ----.----.----.----:290:a9ff:fe0a:71fb > ff02::1:ff76:1ec6: ICMP6, neighbor solicitation, who has ----.----.----.----:6c23:859:3176:1ec6, length 32
20:22:31.319048 IP6 ----.----.----.----:c24a:ff:fedd:4e2e > ff02::1:ff78:3d89: ICMP6, neighbor solicitation, who has ----.----.----.----:d58d:572c:5b78:3d89, length 32
20:22:31.321767 IP6 ----.----.----.----:e695:6eff:fe40:652a > ff02::1:ff78:3d89: ICMP6, neighbor solicitation, who has ----.----.----.----:d58d:572c:5b78:3d89, length 32
20:22:31.323445 IP6 ----.----.----.----:e291:f5ff:fe00:70b7 > ff02::1:fff7:20b6: ICMP6, neighbor solicitation, who has ----.----.----.----:acbd:d21e:c1f7:20b6, length 32
20:22:31.325102 IP6 ----.----.----.----:290:a9ff:feac:2c21 > ff02::1:ff78:3d89: ICMP6, neighbor solicitation, who has ----.----.----.----:d58d:572c:5b78:3d89, length 32
20:22:31.343370 IP6 ----.----.----.----:e291:f5ff:fe00:70b7 > ff02::1:ff72:784e: ICMP6, neighbor solicitation, who has ----.----.----.----:6424:6738:e372:784e, length 32
20:22:31.374977 IP6 ----.----.----.----:e291:f5ff:fe00:70b7 > ff02::1:ffcf:6641: ICMP6, neighbor solicitation, who has ----.----.----.----:2d19:ffb9:d1cf:6641, length 32
20:22:31.378299 IP6 ----.----.----.----:c23f:eff:fe7c:77a8 > ff02::1:ffcf:6641: ICMP6, neighbor solicitation, who has ----.----.----.----:2d19:ffb9:d1cf:6641, length 32
20:22:31.379198 IP6 ----.----.----.----:c23f:eff:fe7c:77a8 > ff02::1:ff28:7b4e: ICMP6, neighbor solicitation, who has ----.----.----.----:3854:5501:cc28:7b4e, length 32
20:22:31.381563 IP6 ----.----.----.----:e695:6eff:fe40:652a > ff02::1:ffcf:6641: ICMP6, neighbor solicitation, who has ----.----.----.----:2d19:ffb9:d1cf:6641, length 32
20:22:31.390391 IP6 ----.----.----.----:c24a:ff:fedd:4e2e > ff02::1:ffcf:6641: ICMP6, neighbor solicitation, who has ----.----.----.----:2d19:ffb9:d1cf:6641, length 32
20:22:31.391852 IP6 ----.----.----.----:c24a:ff:fedd:4e2e > ff02::1:ff4f:2b05: ICMP6, neighbor solicitation, who has ----.----.----.----:f425:368d:474f:2b05, length 32
20:22:31.393423 IP6 ----.----.----.----:e291:f5ff:fe00:70b7 > ff02::1:ff2c:cd43: ICMP6, neighbor solicitation, who has ----.----.----.----:9db5:6935:912c:cd43, length 32
20:22:31.399896 IP6 ----.----.----.----:290:a9ff:fe0a:71fb > ff02::1:ff4f:2b05: ICMP6, neighbor solicitation, who has ----.----.----.----:f425:368d:474f:2b05, length 32
20:22:31.403539 IP6 ----.----.----.----:e291:f5ff:fe00:70b7 > ff02::1:ff4f:2b05: ICMP6, neighbor solicitation, who has ----.----.----.----:f425:368d:474f:2b05, length 32
20:22:31.405243 IP6 ----.----.----.----:290:a9ff:feac:2c21 > ff02::1:ff4f:2b05: ICMP6, neighbor solicitation, who has ----.----.----.----:f425:368d:474f:2b05, length 32
20:22:31.451497 IP6 ----.----.----.----:e695:6eff:fe40:652a > ff02::1:ff45:65ca: ICMP6, neighbor solicitation, who has ----.----.----.----:c907:6475:bb45:65ca, length 32
20:22:31.455172 IP6 ----.----.----.----:290:a9ff:feac:2c21 > ff02::1:ff45:65ca: ICMP6, neighbor solicitation, who has ----.----.----.----:c907:6475:bb45:65ca, length 32
20:22:31.455774 IP6 ----.----.----.----:e291:f5ff:fe00:70b7 > ff02::1:ff45:65ca: ICMP6, neighbor solicitation, who has ----.----.----.----:c907:6475:bb45:65ca, length 32
20:22:31.457361 IP6 ----.----.----.----:c23f:eff:fe7c:77a8 > ff02::1:ff45:65ca: ICMP6, neighbor solicitation, who has ----.----.----.----:c907:6475:bb45:65ca, length 32
20:22:31.468974 IP6 ----.----.----.----:c24a:ff:fedd:4e2e > ff02::1:ff45:65ca: ICMP6, neighbor solicitation, who has ----.----.----.----:c907:6475:bb45:65ca, length 32
20:22:31.481548 IP6 ----.----.----.----:e695:6eff:fe40:652a > ff02::1:ff28:ee0e: ICMP6, neighbor solicitation, who has ----.----.----.----:f86b:f6d6:8428:ee0e, length 32
20:22:31.485020 IP6 ----.----.----.----:290:a9ff:feac:2c21 > ff02::1:ffd2:afdf: ICMP6, neighbor solicitation, who has ----.----.----.----:a93d:5064:1ad2:afdf, length 32
20:22:31.493501 IP6 ----.----.----.----:e291:f5ff:fe00:70b7 > ff02::1:ff28:ee0e: ICMP6, neighbor solicitation, who has ----.----.----.----:f86b:f6d6:8428:ee0e, length 32
20:22:31.493968 IP6 ----.----.----.----:e291:f5ff:fe00:70b7 > ff02::1:ffd2:afdf: ICMP6, neighbor solicitation, who has ----.----.----.----:a93d:5064:1ad2:afdf, length 32
20:22:31.498987 IP6 ----.----.----.----:c24a:ff:fedd:4e2e > ff02::1:ff28:ee0e: ICMP6, neighbor solicitation, who has ----.----.----.----:f86b:f6d6:8428:ee0e, length 32
20:22:31.501784 IP6 ----.----.----.----:e695:6eff:fe40:652a > ff02::1:ffd2:afdf: ICMP6, neighbor solicitation, who has ----.----.----.----:a93d:5064:1ad2:afdf, length 32
20:22:31.502581 IP6 ----.----.----.----:290:a9ff:fe0a:71fb > ff02::1:ffaf:d42b: ICMP6, neighbor solicitation, who has ----.----.----.----:dd55:2a9d:47af:d42b, length 32
20:22:31.506759 IP6 ----.----.----.----:290:a9ff:feac:2c21 > ff02::1:ff28:ee0e: ICMP6, neighbor solicitation, who has ----.----.----.----:f86b:f6d6:8428:ee0e, length 32
20:22:31.507418 IP6 ----.----.----.----:c23f:eff:fe7c:77a8 > ff02::1:ffaf:d42b: ICMP6, neighbor solicitation, who has ----.----.----.----:dd55:2a9d:47af:d42b, length 32
20:22:31.507537 IP6 ----.----.----.----:c23f:eff:fe7c:77a8 > ff02::1:ff28:ee0e: ICMP6, neighbor solicitation, who has ----.----.----.----:f86b:f6d6:8428:ee0e, length 32
20:22:31.509177 IP6 ----.----.----.----:c24a:ff:fedd:4e2e > ff02::1:ffaf:d42b: ICMP6, neighbor solicitation, who has ----.----.----.----:dd55:2a9d:47af:d42b, length 32
20:22:31.509908 IP6 ----.----.----.----:290:a9ff:fe0a:71fb > ff02::1:ff28:ee0e: ICMP6, neighbor solicitation, who has ----.----.----.----:f86b:f6d6:8428:ee0e, length 32
20:22:31.511697 IP6 ----.----.----.----:e695:6eff:fe40:652a > ff02::1:ffaf:d42b: ICMP6, neighbor solicitation, who has ----.----.----.----:dd55:2a9d:47af:d42b, length 32
20:22:31.589949 IP6 ----.----.----.----:290:a9ff:fe0a:71fb > ff02::1:ff68:1854: ICMP6, neighbor solicitation, who has ----.----.----.----:e070:5789:9468:1854, length 32
20:22:31.595038 IP6 ----.----.----.----:290:a9ff:feac:2c21 > ff02::1:ff68:1854: ICMP6, neighbor solicitation, who has ----.----.----.----:e070:5789:9468:1854, length 32
20:22:31.595647 IP6 ----.----.----.----:e291:f5ff:fe00:70b7 > ff02::1:ff68:1854: ICMP6, neighbor solicitation, who has ----.----.----.----:e070:5789:9468:1854, length 32
20:22:31.597299 IP6 ----.----.----.----:c23f:eff:fe7c:77a8 > ff02::1:ff68:1854: ICMP6, neighbor solicitation, who has ----.----.----.----:e070:5789:9468:1854, length 32
20:22:31.599099 IP6 ----.----.----.----:c24a:ff:fedd:4e2e > ff02::1:ff68:1854: ICMP6, neighbor solicitation, who has ----.----.----.----:e070:5789:9468:1854, length 32
20:22:31.607771 IP6 ----.----.----.----:e695:6eff:fe40:652a > ff02::1:ff68:1854: ICMP6, neighbor solicitation, who has ----.----.----.----:e070:5789:9468:1854, length 32
20:22:31.615131 IP6 ----.----.----.----:290:a9ff:feac:2c21 > ff02::1:ff86:89c6: ICMP6, neighbor solicitation, who has ----.----.----.----:60ad:68ca:1686:89c6, length 32
20:22:31.621774 IP6 ----.----.----.----:e695:6eff:fe40:652a > ff02::1:ff86:89c6: ICMP6, neighbor solicitation, who has ----.----.----.----:60ad:68ca:1686:89c6, length 32
20:22:31.622647 IP6 ----.----.----.----:290:a9ff:fe0a:71fb > ff02::1:ff86:89c6: ICMP6, neighbor solicitation, who has ----.----.----.----:60ad:68ca:1686:89c6, length 32



Sample from logread:


Sat Mar  4 20:28:41 2017 daemon.notice odhcpd[1724]: Forgot about ----.----.----.----:79d2:b259:6f7f:b4d0 on eth0
Sat Mar  4 20:28:41 2017 daemon.notice odhcpd[1724]: Forgot about ----.----.----.----:f425:368d:474f:2b05 on eth0
Sat Mar  4 20:28:41 2017 daemon.notice odhcpd[1724]: Forgot about ----.----.----.----:f914:3130:37e9:11f6 on eth0
Sat Mar  4 20:28:41 2017 daemon.notice odhcpd[1724]: Forgot about ----.----.----.----:f86b:f6d6:8428:ee0e on eth0
Sat Mar  4 20:28:41 2017 daemon.notice odhcpd[1724]: Forgot about ----.----.----.----:e852:37cf:eb0d:6ec6 on eth0
Sat Mar  4 20:28:41 2017 daemon.notice odhcpd[1724]: Forgot about ----.----.----.----:dd55:2a9d:47af:d42b on eth0
Sat Mar  4 20:28:41 2017 daemon.notice odhcpd[1724]: Forgot about ----.----.----.----:65e5:7c5d:a3fe:5a3 on eth0
Sat Mar  4 20:28:41 2017 daemon.notice odhcpd[1724]: Forgot about ----.----.----.----:290:a9ff:fe0a:71fb on eth0
Sat Mar  4 20:28:41 2017 daemon.notice odhcpd[1724]: Forgot about ----.----.----.----:945b:446d:a137:71fa on eth0
Sat Mar  4 20:28:41 2017 daemon.notice odhcpd[1724]: Forgot about ----.----.----.----:d4ca:9bcf:b16f:fa1c on eth0
Sat Mar  4 20:28:41 2017 daemon.notice odhcpd[1724]: Forgot about ----.----.----.----:98b8:cca6:a4ae:777a on eth0
Sat Mar  4 20:28:41 2017 daemon.notice odhcpd[1724]: Forgot about ----.----.----.----:3150:4be0:2276:1e58 on eth0
Sat Mar  4 20:28:41 2017 daemon.notice odhcpd[1724]: Forgot about ----.----.----.----:d58d:572c:5b78:3d89 on eth0
Sat Mar  4 20:28:41 2017 daemon.notice odhcpd[1724]: Learned about ----.----.----.----::1 on eth0
Sat Mar  4 20:28:41 2017 daemon.notice odhcpd[1724]: Learned about ----.----.----.----:1:d00d::40 on eth0
Sat Mar  4 20:28:41 2017 daemon.notice odhcpd[1724]: Learned about ----.----.----.----:b859:fcda:2fa4:f901 on eth0
Sat Mar  4 20:28:56 2017 daemon.notice odhcpd[1724]: Forgot about ----.----.----.----:f86b:f6d6:8428:ee0e on eth0
Sat Mar  4 20:28:56 2017 daemon.notice odhcpd[1724]: Forgot about ----.----.----.----:dd55:2a9d:47af:d42b on eth0
Sat Mar  4 20:28:56 2017 daemon.notice odhcpd[1724]: Forgot about ----.----.----.----:8c42:9741:e071:2d25 on eth0
Sat Mar  4 20:28:56 2017 daemon.notice odhcpd[1724]: Forgot about ----.----.----.----:a93d:5064:1ad2:afdf on eth0
Sat Mar  4 20:28:56 2017 daemon.notice odhcpd[1724]: Forgot about ----.----.----.----:f425:368d:474f:2b05 on br-lan
Sat Mar  4 20:28:56 2017 daemon.notice odhcpd[1724]: Forgot about ----.----.----.----:1:d00d::40 on eth0
Sat Mar  4 20:28:56 2017 daemon.notice odhcpd[1724]: Forgot about ----.----.----.----:b859:fcda:2fa4:f901 on eth0
Sat Mar  4 20:28:56 2017 daemon.notice odhcpd[1724]: Forgot about ----.----.----.----:3150:4be0:2276:1e58 on eth0
Sat Mar  4 20:28:56 2017 daemon.notice odhcpd[1724]: Learned about ----.----.----.----::1 on eth0
Sat Mar  4 20:29:11 2017 daemon.notice odhcpd[1724]: Forgot about ----.----.----.----:79d2:b259:6f7f:b4d0 on eth0
Sat Mar  4 20:29:11 2017 daemon.notice odhcpd[1724]: Forgot about ----.----.----.----:f86b:f6d6:8428:ee0e on eth0
Sat Mar  4 20:29:11 2017 daemon.notice odhcpd[1724]: Forgot about ----.----.----.----:acbd:d21e:c1f7:20b6 on eth0
Sat Mar  4 20:29:11 2017 daemon.notice odhcpd[1724]: Forgot about ----.----.----.----:dd55:2a9d:47af:d42b on eth0
Sat Mar  4 20:29:11 2017 daemon.notice odhcpd[1724]: Forgot about ----.----.----.----:60ad:68ca:1686:89c6 on eth0
Sat Mar  4 20:29:11 2017 daemon.notice odhcpd[1724]: Forgot about ----.----.----.----::1 on br-lan
Sat Mar  4 20:29:11 2017 daemon.notice odhcpd[1724]: Forgot about ----.----.----.----:65e5:7c5d:a3fe:5a3 on eth0
Sat Mar  4 20:29:11 2017 daemon.notice odhcpd[1724]: Forgot about ----.----.----.----:3854:5501:cc28:7b4e on eth0
Sat Mar  4 20:29:11 2017 daemon.notice odhcpd[1724]: Forgot about ----.----.----.----:bcc1:bb13:d978:6cf on eth0
Sat Mar  4 20:29:11 2017 daemon.notice odhcpd[1724]: Forgot about ----.----.----.----:d58d:572c:5b78:3d89 on eth0
Sat Mar  4 20:29:11 2017 daemon.notice odhcpd[1724]: Learned about ----.----.----.----::1 on eth0
Sat Mar  4 20:29:15 2017 daemon.notice odhcpd[1724]: Learned about ----.----.----.----::1 on eth0
Sat Mar  4 20:29:15 2017 daemon.notice odhcpd[1724]: Learned about ----.----.----.----::1 on eth0
Sat Mar  4 20:29:25 2017 daemon.notice odhcpd[1724]: Learned about ----.----.----.----:1:d00d::40 on eth0
Sat Mar  4 20:29:26 2017 daemon.notice odhcpd[1724]: Forgot about ----.----.----.----:f914:3130:37e9:11f6 on eth0
Sat Mar  4 20:29:26 2017 daemon.notice odhcpd[1724]: Forgot about ----.----.----.----:dd55:2a9d:47af:d42b on eth0
Sat Mar  4 20:29:26 2017 daemon.notice odhcpd[1724]: Forgot about ----.----.----.----:6424:6738:e372:784e on eth0
Sat Mar  4 20:29:26 2017 daemon.notice odhcpd[1724]: Forgot about ----.----.----.----:e695:6eff:fe40:652a on br-lan
Sat Mar  4 20:29:26 2017 daemon.notice odhcpd[1724]: Forgot about ----.----.----.----:3854:5501:cc28:7b4e on eth0
Sat Mar  4 20:29:26 2017 daemon.notice odhcpd[1724]: Forgot about ----.----.----.----:8c42:9741:e071:2d25 on eth0
Sat Mar  4 20:29:26 2017 daemon.notice odhcpd[1724]: Forgot about ----.----.----.----:bcc1:bb13:d978:6cf on eth0
Sat Mar  4 20:29:26 2017 daemon.notice odhcpd[1724]: Forgot about ----.----.----.----:e070:5789:9468:1854 on eth0
Sat Mar  4 20:29:26 2017 daemon.notice odhcpd[1724]: Forgot about ----.----.----.----:3150:4be0:2276:1e58 on eth0
Sat Mar  4 20:29:26 2017 daemon.notice odhcpd[1724]: Learned about ----.----.----.----::1 on eth0
Sat Mar  4 20:29:26 2017 daemon.notice odhcpd[1724]: Learned about ----.----.----.----:1:d00d::40 on eth0



More information can be found at the following URL:
https://bugs.lede-project.org/index.php?do=details&task_id=595

More information about the lede-bugs mailing list