A number of network addresses appear to be unreachable from my computer (Mac Mavericks, 10.9.2). For example I do not see any images on wikipedia. Today's featured article does not show the image http://upload.wikimedia.org/wikipedia/commons/5/54/Potret_Roekiah1.jpg (Safari times out trying to load the image).
Here are my attempts of understanding what's going on (I did edit ids and some ip numbers).
[Radek ~]$ ping upload.wikimedia.org PING upload-lb.esams.wikimedia.org (18.104.22.168): 56 data bytes 36 bytes from ae2.cr1-esams.wikimedia.org (22.214.171.124): Destination Net Unreachable Vr HL TOS Len ID Flg off TTL Pro cks Src Dst 4 5 48 5400 e066 0 0000 3c 01 d18f 192.168.1.18 126.96.36.199 Request timeout for icmp_seq 0 Request timeout for icmp_seq 1
(and ping times-out or reports
Destination Net Unreachable for other attempts)
[Radek ~]$ traceroute upload.wikimedia.org traceroute to upload-lb.esams.wikimedia.org (188.8.131.52), 64 hops max, 52 byte packets 1 192.168.1.1 (192.168.1.1) 2.359 ms 2.102 ms 2.016 ms 2 xxx.adsl2.static.versatel.nl (82.173.xx.xx) 104.734 ms 106.157 ms 107.574 ms 3 xxx.xxx.versatel.net (184.108.40.206) 125.938 ms * 49.443 ms 4 ae6-xxx.brxxxsara.versatel.net (212.53.xx.xx) 55.765 ms 66.818 ms 80.532 ms 5 * * * ... 64 * * *
Here are some details of my configuration:
[Radek ~]$ ifconfig -a lo0: flags=8049<UP,LOOPBACK,RUNNING,MULTICAST> mtu 16384 options=3<RXCSUM,TXCSUM> inet6 ::1 prefixlen 128 inet 127.0.0.1 netmask 0xff000000 inet6 fe80::1%lo0 prefixlen 64 scopeid 0x1 nd6 options=1<PERFORMNUD> gif0: flags=8010<POINTOPOINT,MULTICAST> mtu 1280 stf0: flags=0<> mtu 1280 en0: flags=8863<UP,BROADCAST,SMART,RUNNING,SIMPLEX,MULTICAST> mtu 1500 ether xx:xx inet6 xxxx:xxxx%en0 prefixlen 64 scopeid 0x4 inet 192.168.1.18 netmask 0xffffff00 broadcast 192.168.1.255 nd6 options=1<PERFORMNUD> media: autoselect status: active en1: flags=8963<UP,BROADCAST,SMART,RUNNING,PROMISC,SIMPLEX,MULTICAST> mtu 1500 options=60<TSO4,TSO6> ether xx:xx media: autoselect <full-duplex> status: inactive en2: flags=8863<UP,BROADCAST,SMART,RUNNING,SIMPLEX,MULTICAST> mtu 1500 options=60<TSO4,TSO6> ether xx:xx nd6 options=1<PERFORMNUD> media: autoselect <full-duplex> status: inactive bridge0: flags=8863<UP,BROADCAST,SMART,RUNNING,SIMPLEX,MULTICAST> mtu 1500 options=63<RXCSUM,TXCSUM,TSO4,TSO6> ether xx:xx Configuration: id 0:0:0:0:0:0 priority 0 hellotime 0 fwddelay 0 maxage 0 holdcnt 0 proto stp maxaddr 100 timeout 1200 root id 0:0:0:0:0:0 priority 0 ifcost 0 port 0 ipfilter disabled flags 0x2 member: en1 flags=3<LEARNING,DISCOVER> ifmaxaddr 0 port 6 priority 0 path cost 0 nd6 options=1<PERFORMNUD> media: <unknown type> status: inactive p2p0: flags=8843<UP,BROADCAST,RUNNING,SIMPLEX,MULTICAST> mtu 2304 ether xx:xx media: autoselect status: inactive [Radek ~]$ netstat -s tcp: 4041934 packets sent 2109154 data packets (2412741336 bytes) 4336 data packets (4973578 bytes) retransmitted 0 resends initiated by MTU discovery 1515058 ack-only packets (788 delayed) 0 URG only packets 8 window probe packets 315897 window update packets 98042 control packets 997 data packets sent after flow control 3032003 checksummed in software 3032003 segments (2030699244 bytes) over IPv4 0 segments (0 bytes) over IPv6 4874936 packets received 1245553 acks (for 2412436596 bytes) 61704 duplicate acks 0 acks for unsent data 3590173 packets (4105070383 bytes) received in-sequence 4782 completely duplicate packets (2495220 bytes) 881 old duplicate packets 103 packets with some dup. data (44979 bytes duped) 88880 out-of-order packets (119408758 bytes) 0 packets (0 bytes) of data after window 0 window probes 1297 window update packets 2853 packets received after close 0 bad resets 1 discarded for bad checksum 3221507 checksummed in software 3221507 segments (2755880532 bytes) over IPv4 0 segments (0 bytes) over IPv6 0 discarded for bad header offset fields 0 discarded because packet too short 53415 connection requests 11 connection accepts 0 bad connection attempts 0 listen queue overflows 45391 connections established (including accepts) 53529 connections closed (including 5839 drops) 742 connections updated cached RTT on close 742 connections updated cached RTT variance on close 258 connections updated cached ssthresh on close 5357 embryonic connections dropped 2919226 segments updated rtt (of 1129684 attempts) 7233 retransmit timeouts 44 connections dropped by rexmit timeout 0 connections dropped after retransmitting FIN 21 persist timeouts 0 connections dropped by persist timeout 137 keepalive timeouts 1 keepalive probe sent 84 connections dropped by keepalive 522089 correct ACK header predictions 3349375 correct data packet header predictions 1800 SACK recovery episodes 3142 segment rexmits in SACK recovery episodes 4404841 byte rexmits in SACK recovery episodes 40073 SACK options (SACK blocks) received 88105 SACK options (SACK blocks) sent 0 SACK scoreboard overflow 0 LRO coalesced packets 0 times LRO flow table was full 0 collisions in LRO flow table 0 times LRO coalesced 2 packets 0 times LRO coalesced 3 or 4 packets 0 times LRO coalesced 5 or more packets 2627 limited transmits done 1212 early retransmits done 1495 times cumulative ack advanced along with SACK udp: 1116361 datagrams received 0 with incomplete header 0 with bad data length field 0 with bad checksum 1 with no checksum 831232 checksummed in software 814776 datagrams (107515088 bytes) over IPv4 16456 datagrams (5525356 bytes) over IPv6 463 dropped due to no socket 588682 broadcast/multicast datagrams undelivered 0 times multicast source filter matched 0 dropped due to full socket buffers 0 not for hashed pcb 527216 delivered 68356 datagrams output 57620 checksummed in software 50288 datagrams (3553575 bytes) over IPv4 7332 datagrams (1789298 bytes) over IPv6 ip: 6126838 total packets received 0 bad header checksums 4194980 headers (83905872 bytes) checksummed in software 0 with size smaller than minimum 0 with data size < data length 154979 with data size > data length 0 packets forced to software checksum 0 with ip length > max ip packet size 0 with header length < data size 0 with data length < header length 0 with bad options 0 with incorrect version number 121 fragments received 0 dropped (dup or out of space) 0 dropped after timeout 60 reassembled ok 5964502 packets for this host 7957 packets for unknown/unsupported protocol 0 packets forwarded (0 packets fast forwarded) 2108 packets not forwardable 152210 packets received for unknown multicast group 0 redirects sent 4125494 packets sent from this host 305 packets sent with fabricated ip header 0 output packets dropped due to no bufs, etc. 3 output packets discarded due to no route 0 output datagrams fragmented 0 fragments created 0 datagrams that can't be fragmented 0 tunneling packets that can't find gif 0 datagrams with bad address in header 0 packets dropped due to no bufs for control data 3091053 headers (61835944 bytes) checksummed in software icmp: 463 calls to icmp_error 0 errors not generated 'cuz old message was icmp Output histogram: echo reply: 4 destination unreachable: 463 0 messages with bad code fields 0 messages < minimum length 0 bad checksums 0 messages with bad length 0 multicast echo requests ignored 0 multicast timestamp requests ignored Input histogram: echo reply: 100 destination unreachable: 6099 echo: 4 time exceeded: 71 4 message responses generated ICMP address mask responses are disabled igmp: 1971 messages received 0 messages received with too few bytes 1 message received with wrong TTL 0 messages received with bad checksum 1963 V1/V2 membership queries received 0 V3 membership queries received 0 membership queries received with invalid field(s) 1963 general queries received 0 group queries received 0 group-source queries received 0 group-source queries dropped 7 membership reports received 0 membership reports received with invalid field(s) 7 membership reports received for groups to which we belong 0 V3 reports received without Router Alert 3506 membership reports sent ipsec: 0 inbound packets processed successfully 0 inbound packets violated process security policy 0 inbound packets with no SA available 0 invalid inbound packets 0 inbound packets failed due to insufficient memory 0 inbound packets failed getting SPI 0 inbound packets failed on AH replay check 0 inbound packets failed on ESP replay check 0 inbound packets considered authentic 0 inbound packets failed on authentication 0 outbound packets processed successfully 0 outbound packets violated process security policy 0 outbound packets with no SA available 0 invalid outbound packets 0 outbound packets failed due to insufficient memory 0 outbound packets with no route arp: 1236 ARP requests sent 1838 ARP replies sent 0 ARP announcements sent 171129 ARP requests received 1141 ARP replies received 172326 total ARP packets received 0 ARP conflict probes sent 0 invalid ARP resolve requests 0 total packets dropped due to lack of memory 2014 total packets dropped due to no ARP entry 71 total packets dropped during ARP entry removal 960 ARP entries timed out 0 Duplicate IPs seen ip6: 33159 total packets received 0 with size smaller than minimum 0 with data size < data length 0 with data size > data length 0 packets forced to software checksum 0 with bad options 0 with incorrect version number 1208 fragments received 0 dropped (dup or out of space) 0 dropped after timeout 0 exceeded limit 604 reassembled ok 27697 packets for this host 0 packets forwarded 4297 packets not forwardable 0 redirects sent 4297 multicast packets which we don't join 0 packets whose headers are not continuous 0 tunneling packets that can't find gif 0 packets discarded due to too may headers 0 forward cache hit 0 forward cache miss 0 packets dropped due to no bufs for control data 5010 packets sent from this host 0 packets sent with fabricated ip header 0 output packets dropped due to no bufs, etc. 5782 output packets discarded due to no route 0 output datagrams fragmented 0 fragments created 0 datagrams that can't be fragmented 0 packets that violated scope rules Input histogram: hop by hop: 62 TCP: 30 UDP: 26459 fragment: 1208 ICMP6: 5397 Mbuf statistics: 7285 one mbuf two or more mbuf: lo0= 4535 21339 one ext mbuf 0 two or more ext mbuf 0 failures of source address selection icmp6: 0 calls to icmp_error 0 errors not generated because old message was icmp error or so 0 errors not generated because rate limitation Output histogram: router solicitation: 186 neighbor solicitation: 73 neighbor advertisement: 73 MLDv2 listener report: 113 0 messages with bad code fields 0 messages < minimum length 0 bad checksums 0 messages with bad length Input histogram: MLDv1 listener report: 50 neighbor solicitation: 21 neighbor advertisement: 1091 Histogram of error messages to be generated: 0 no route 0 administratively prohibited 0 beyond scope 0 address unreachable 0 port unreachable 0 packet too big 0 time exceed transit 0 time exceed reassembly 0 erroneous header field 0 unrecognized next header 0 unrecognized option 0 redirect 0 unknown 0 message responses generated 0 messages with too many ND options 0 messages with bad ND options 0 bad neighbor solicitation messages 19 bad neighbor advertisement messages 0 bad router solicitation messages 0 bad router advertisement messages 0 bad redirect messages 0 path MTU changes ipsec6: 0 inbound packets processed successfully 0 inbound packets violated process security policy 0 inbound packets with no SA available 0 invalid inbound packets 0 inbound packets failed due to insufficient memory 0 inbound packets failed getting SPI 0 inbound packets failed on AH replay check 0 inbound packets failed on ESP replay check 0 inbound packets considered authentic 0 inbound packets failed on authentication 0 outbound packets processed successfully 0 outbound packets violated process security policy 0 outbound packets with no SA available 0 invalid outbound packets 0 outbound packets failed due to insufficient memory 0 outbound packets with no route rip6: 0 messages received 0 checksum calcurations on inbound 0 messages with bad checksum 0 messages dropped due to no socket 0 multicast messages dropped due to no socket 0 messages dropped due to full socket buffers 0 delivered 0 datagrams output pfkey: 0 requests sent to userland 0 bytes sent to userland 0 messages with invalid length field 0 messages with invalid version field 0 messages with invalid message type field 0 messages too short 0 messages with memory allocation failure 0 messages with duplicate extension 0 messages with invalid extension type 0 messages with invalid sa type 0 messages with invalid address extension 0 requests sent from userland 0 bytes sent from userland 0 messages toward single socket 0 messages toward all sockets 0 messages toward registered sockets 0 messages with memory allocation failure
The problem is specific to my Mac (wikipedia works on iOS devices) and persists despite trying:
- different networks (fails at work and at home)
- different interfaces (via wi-fi or ethernet)
- reboot (even system updates, currently 10.9.2)
- different DNS ("automatic" as well as google 220.127.116.11 and 18.104.22.168)
Solved! Thanks.... It was a "VPN over ssh" client sshuttle that changed my
/etc/hosts file to redirect from wikimedia (among >1000 others…)