(updated) failed: No route to host

Livestradamus · 12-01-2020, 06:26 AM

On one of my -current boxes is receiving many errors failed no route to host
Resolving slackware.uk... 2a02:2498:1:227::240, 91.109.244.240 when running any command with slackpkg. I suspect some network related but I have another box running current with same settings (network, slackpkg has exact copies of files) and no such errors. I have tried different mirrors.
The application is working, but not getting rid of that error.

Code:

failed: No route to host

update: it's happening when trying to connect and download from IPv6 address
update: its certainly not slackpkg's doing but my overlooked network configurations

This is my slackpkg.conf

Code:

#
TEMP=/var/cache/packages
WORKDIR=/var/lib/slackpkg
WGETFLAGS="--passive-ftp"
DELALL=on
CHECKMD5=on
CHECKGPG=on
CHECKSIZE=off
PRIORITY=( testing patches %PKGMAIN extra pasture )
POSTINST=on
ONLY_NEW_DOTNEW=off
ONOFF=on
DOWNLOAD_ALL=on
DIALOG=on
BATCH=off
DEFAULT_ANSWER=n
USE_INCLUDES=on
SPINNING=on
DIALOG_MAXARGS=139000

And this is my slackpkgplus.conf

Code:

SLACKPKGPLUS=on
VERBOSE=1
ALLOW32BIT=off
USEBL=1
WGETOPTS="--timeout=20 --tries=2"
SEARCH_CLOG_INPARENT=on
CACHEUPDATE=off
GREYLIST=on
SENSITIVE_SEARCH=on
WW_FILE_SEARCH=on
SHOWORDER=package
DETAILED_INFO=none
STRICTGPG=on
TAG_PRIORITY=off
REPOPLUS=( slackpkgplus alienbob )
MIRRORPLUS['slackpkgplus']=http://slakfinder.org/slackpkg+/
MIRRORPLUS['alienbob']=http://bear.alienbase.nl/mirrors/people/alien/sbrepos/current/x86_64/

And the mirrors

Code:

https://mirrors.slackware.com/slackware/slackware64-current/

Ser Olmy · 12-01-2020, 06:25 PM

Your issue seems to be IPv6 connectivity, and probably isn't related to slackpkg at all.

What's the output of ip -6 addr list?

What does traceroute6 2a02:2498:1:227::240 report? How about traceroute6 2600:: and ping6 2600::?

Livestradamus · 12-02-2020, 12:04 AM

Code:

$ traceroute6 2a02:2498:1:227::240
traceroute to 2a02:2498:1:227::240 (2a02:2498:1:227::240) from 2001:16a2:a26:c600:f2a9:1d2b:2c60:c726, 30 hops max, 24 byte packets
 1  2001:16a2:a26:c600:f2a9:1d2b:2c60:c726 (2001:16a2:a26:c600:f2a9:1d2b:2c60:c726)  3004.41 ms !H  3006.45 ms !H  3006.99 ms !H

Code:

$ ip -6 addr list
1: lo: <LOOPBACK,UP,LOWER_UP> mtu 65536 state UNKNOWN qlen 1
    inet6 ::1/128 scope host 
       valid_lft forever preferred_lft forever
2: eth0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 state UP qlen 1000
    inet6 2001:16a2:a26:c600:f2a9:1d2b:2c60:c726/64 scope global noprefixroute dynamic 
       valid_lft 86172sec preferred_lft 86172sec
    inet6 fe80::a21d:48ff:feb0:3e6a/64 scope link 
       valid_lft forever preferred_lft forever

Code:

$ traceroute6 2600:: 
traceroute to 2600:: (2600::) from 2001:16a2:a26:c600:f2a9:1d2b:2c60:c726, 30 hops max, 24 byte packets
 1  2001:16a2:a26:c600:f2a9:1d2b:2c60:c726 (2001:16a2:a26:c600:f2a9:1d2b:2c60:c726)  3006.98 ms !H  3005.49 ms !H  3005.99 ms !H

Code:

$ ping6 2600::
PING 2600::(2600::) 56 data bytes
From 2001:16a2:a26:c600:f2a9:1d2b:2c60:c726 icmp_seq=1 Destination unreachable: Address unreachable
From 2001:16a2:a26:c600:f2a9:1d2b:2c60:c726 icmp_seq=2 Destination unreachable: Address unreachable
From 2001:16a2:a26:c600:f2a9:1d2b:2c60:c726 icmp_seq=3 Destination unreachable: Address unreachable
From 2001:16a2:a26:c600:f2a9:1d2b:2c60:c726 icmp_seq=4 Destination unreachable: Address unreachable
From 2001:16a2:a26:c600:f2a9:1d2b:2c60:c726 icmp_seq=5 Destination unreachable: Address unreachable
From 2001:16a2:a26:c600:f2a9:1d2b:2c60:c726 icmp_seq=6 Destination unreachable: Address unreachable
From 2001:16a2:a26:c600:f2a9:1d2b:2c60:c726 icmp_seq=7 Destination unreachable: Address unreachable
From 2001:16a2:a26:c600:f2a9:1d2b:2c60:c726 icmp_seq=8 Destination unreachable: Address unreachable
From 2001:16a2:a26:c600:f2a9:1d2b:2c60:c726 icmp_seq=9 Destination unreachable: Address unreachable
From 2001:16a2:a26:c600:f2a9:1d2b:2c60:c726 icmp_seq=10 Destination unreachable: Address unreachable
From 2001:16a2:a26:c600:f2a9:1d2b:2c60:c726 icmp_seq=11 Destination unreachable: Address unreachable
From 2001:16a2:a26:c600:f2a9:1d2b:2c60:c726 icmp_seq=12 Destination unreachable: Address unreachable
From 2001:16a2:a26:c600:f2a9:1d2b:2c60:c726 icmp_seq=13 Destination unreachable: Address unreachable
From 2001:16a2:a26:c600:f2a9:1d2b:2c60:c726 icmp_seq=14 Destination unreachable: Address unreachable
From 2001:16a2:a26:c600:f2a9:1d2b:2c60:c726 icmp_seq=15 Destination unreachable: Address unreachable
From 2001:16a2:a26:c600:f2a9:1d2b:2c60:c726 icmp_seq=16 Destination unreachable: Address unreachable
^C
--- 2600:: ping statistics ---
17 packets transmitted, 0 received, +16 errors, 100% packet loss, time 16005ms

Ser Olmy · 12-02-2020, 12:27 AM

Your PC has a valid global IPv6 address, but seems to lack a (default) route to the Internet. This could be a problem with your router, or perhaps your kernel isn't configured to listen to IPv6 Router Advertisements.

What does ip -6 route list say? Does it show a "default" route?

Does cat /proc/sys/net/ipv6/conf/eth0/accept_ra and cat /proc/sys/net/ipv6/conf/eth0/accept_ra_defrtr return a 1 or a 0?

Livestradamus · 12-02-2020, 12:59 AM

I am using a bridge to this box because I couldn't pull a cable. And the bridge is an old repurposed router device running one of the foss linux based router os's.
I will work to check and reconfigure if needed over the weeknd.

Code:

$ ip -6 route list
2001:16a2:a26:c600::/64 dev eth0  proto ra  metric 100  pref medium
fe80::1 dev eth0  proto static  metric 100  pref medium
fe80::/64 dev eth0  proto kernel  metric 256  mtu 1472 pref medium
default via fe80::1 dev eth0  proto static  metric 100  pref medium

Code:

$ cat /proc/sys/net/ipv6/conf/eth0/accept_ra
1

Code:

$ cat /proc/sys/net/ipv6/conf/eth0/accept_ra_defrtr
0

Ser Olmy · 12-02-2020, 01:24 AM

Quote:

Originally Posted by Livestradamus

Code:

$ ip -6 route list
2001:16a2:a26:c600::/64 dev eth0  proto ra  metric 100  pref medium
fe80::1 dev eth0  proto static  metric 100  pref medium
fe80::/64 dev eth0  proto kernel  metric 256  mtu 1472 pref medium
default via fe80::1 dev eth0  proto static  metric 100  pref medium

The text in red does not really make sense.

First, there seems to be a device on your network with "fe80::1" as its link-local address. That is indeed a valid address, but extremely unusual as the link-local address is supposed to be generated either based on the 48-bit MAC address of the NIC with a "ff:fe" inserted in the middle to pad the lower half of the address to the full 64-bit, or alternatively the so-called "privacy extensions" to IPv6 (if supported by the device) will generate a completely random address.

There's just no way either algorithm would result in fe80::1, so something weird is going on here.

Second, even though this address is listed as the default gateway, attempts to ping non-local addresses result in "unreachable" errors from your own PC. That's definitely wrong, as it indicates that the first hop router (the previously mentioned fe80::1) cannot be reached.

Try running ip -6 neigh show before and after ping6 fe80::1. It should tell you whether or not a device with that address actually exists.

Quote:

Originally Posted by Livestradamus

Code:

$ cat /proc/sys/net/ipv6/conf/eth0/accept_ra
1

Code:

$ cat /proc/sys/net/ipv6/conf/eth0/accept_ra_defrtr
0

It seems your IP stack is configured to reject default routes offered via Router Advertisements. Try:

Code:

sudo echo 1 > /proc/sys/net/ipv6/conf/eth0/accept_ra_defrtr

and see if the default route reported by ip -6 route list changes after a few seconds.

If it does, you can try ping6 2600:: and ip -6 neigh show again.