ipv6 default route is not installed even though its gets the RA

B

bigbrother

Hi,

My Ipv6 FreeBSD was used to operate successfully in the past. These days, after many binary upgrades my ipv6 default route is not installed any more and I have created a script as a workarround that I am displaying in the end of this post. I am using the same configuration into different ipv6 networks and different machines (all with the same setup), so I can assume that I am missing something.

On all my machines, I use the same firewall rules and the same settings. On my rc.conf I have:

Code: 
#enable ipv6
ipv6_network_interfaces="re0"
ifconfig_re0_ipv6="inet6 accept_rtadv"
ipv6_activate_all_interfaces="YES"
ip6addrctl_policy="ipv6_prefer"
rtsold_enable="YES"
rtsold_flags="-aF"

I have disabled the firewall using a
ipfw add 1 allow all from any to any

My network card gets an IPv6 and can ping local ipv6 hosts.
But It does not get a default route, which I can verify if I view the

netstat -nr

(I see there only a default route for ipv4).

Using -dD flags on the rtsol or tcpdump -n -i em0 icmp6 I can verify that I receive router advertisement (tested on 4-5 freebsd machines (
12.2-RELEASE-p7 FreeBSD 12.2-RELEASE-p7 GENERIC amd64 ) but no default route is ever installed, and thus I cannot ping or traceroute.

Example:

Code: 
# traceroute6 google.com
connect: No route to host

The rtsol output that shows the RA received, but nothing is installed in the routing table.
Also note that I have tried either by net.inet6.ip6.accept_rtadv=1 or net.inet6.ip6.accept_rtadv=0

Code: 
# rtsol -Dd em0
rtsol: checking if em0 is ready...
rtsol: em0 is ready
rtsol: set timer for em0 to 0s
rtsol: New timer is 0s
rtsol: timer expiration on em0, state = 1
rtsol: set timer for em0 to 4s
rtsol: New timer is 4s
rtsol: received RA from fe80::21e:13ff:fe40:8e7f on em0, state is 2
rtsol: Processing RA
rtsol: ndo = 0x7fffffffe220
rtsol: ndo->nd_opt_type = 1
rtsol: ndo->nd_opt_len = 1
rtsol: ndo = 0x7fffffffe228
rtsol: ndo->nd_opt_type = 5
rtsol: ndo->nd_opt_len = 1
rtsol: ndo = 0x7fffffffe230
rtsol: ndo->nd_opt_type = 3
rtsol: ndo->nd_opt_len = 4
rtsol: rsid = [em0:slaac]
rtsol: stop timer for em0
rtsol: there is no timer

To solve this as a workarround I have created the script at the end of this message, that parses the rtsol RA and installs the default route if absent. It works, but I would like to know why the default route is not installed, and what else should I look to fix it without this workarround.

the script that I have created for workarround to install a default ipv6 route is:

Code: 
#!/bin/sh
# If not default gateway is present, do setup one
# 2021.08.14 First Version, Minas

tmpfile=/tmp/$$.rtsol.txt



#ipv6 routes carry a : (xx:xx:xx) , while ipv4 carry dots (x.x.x.x)
ipv6gw=`netstat -nr | grep default | awk '{print $2}' | grep ':'`

# If this is not empty, we have a default ipv6 route
if [ ! -z "$ipv6gw" ] ; then
        exit
fi

# if we are here we have to setup a default ipv6
rtsol -Dda > $tmpfile 2>&1
ipv6gw=`cat $tmpfile | grep received | tr -d ',' | awk '{print $5"%"$7}'`
echo "$0 Adding GW [$ipv6gw]"
route add -6 default $ipv6gw
rm $tmpfile


Any insights on ipv6 default gateway? Thanks!
 
Some of my machines are using em0 and some re0. Of course on the rc.conf I have setup either em0 or re0 for each machine. All the rest are the same.
 
bigbrother said:
Also note that I have tried either by net.inet6.ip6.accept_rtadv=1 or net.inet6.ip6.accept_rtadv=0
Click to expand...
To answer to VladiBG question, I have experimented by using a value of 0 or a value for 1 for net.inet6.ip6.accept_rtadv and nothing happened. I assume that '1' is the suggested value, but I did not notice any different either by 1 or by 0.
 
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