systemd-networkd vs yggdrasil

[whoizit]

OS: Arch Linux (updated)

~ $ yggdrasil -version
Build name: yggdrasil
Build version: 0.3.12

~ $ systemctl --version
systemd 244 (244.1-1-arch)
+PAM +AUDIT -SELINUX -IMA -APPARMOR +SMACK -SYSVINIT +UTMP +LIBCRYPTSETUP +GCRYPT +GNUTLS +ACL +XZ +LZ4 +SECCOMP +BLKID +ELFUTILS +KMOD +IDN2 -IDN +PCRE2 default-hierarchy=hybrid

~ $ sudo yggdrasil -autoconf
2019/12/24 21:49:26 Build name: yggdrasil
2019/12/24 21:49:26 Build version: 0.3.12
2019/12/24 21:49:26 Starting up...
2019/12/24 21:49:26 Starting switch
2019/12/24 21:49:26 Starting router
2019/12/24 21:49:26 Startup complete
2019/12/24 21:49:26 Starting multicast module
2019/12/24 21:49:26 Listening for TCP on: [fe80::d63d:7eff:fef5:98ec%enp4s0]:38839
2019/12/24 21:49:26 UNIX admin socket listening on /var/run/yggdrasil.sock
2019/12/24 21:49:26 Interface name: tun0
2019/12/24 21:49:26 Interface IPv6: 200:338:82c:7578:661:e241:ffa0:e62f/7
2019/12/24 21:49:26 Interface MTU: 65535
2019/12/24 21:49:26 Your IPv6 address is 200:338:82c:7578:661:e241:ffa0:e62f
2019/12/24 21:49:26 Your IPv6 subnet is 300:338:82c:7578::/64
2019/12/24 21:49:26 Connected TCP: 200:9735:aebd:4d23:9b3d:5927:f99a:4eec@fe80::ea94:f6ff:fe58:d10e%enp4s0, source fe80::d63d:7eff:fef5:98ec%enp4s0

~ $ sudo yggdrasilctl getPeers
                                        bytes_recvd  bytes_sent  endpoint                                        port  proto  uptime         
200:338:82c:7578:661:e241:ffa0:e62f     3032         3040        (self)                                          0     self   00:03:51       
200:9735:aebd:4d23:9b3d:5927:f99a:4eec  4776         3032        tcp://[fe80::ea94:f6ff:fe58:d10e%enp4s0]:33033  1     tcp    00:03:51   

~ $ ip a s tun0
7: tun0: <POINTOPOINT,MULTICAST,NOARP,UP,LOWER_UP> mtu 65535 qdisc fq_codel state UNKNOWN group default qlen 500
    link/none 
    inet6 fe80::6764:d16b:ef05:39de/64 scope link stable-privacy 
       valid_lft forever preferred_lft forever

~ $ networkctl 
IDX LINK   TYPE     OPERATIONAL SETUP     
  1 lo     loopback carrier     configured
  2 enp4s0 ether    routable    configured
  7 tun0   none     degraded    configured

3 links listed.

settings in /etc/systemd/network* is default

~ $ cat /etc/systemd/network/*
[Match]
Name=en*

[Network]
DHCP=ipv4
#[Network]
#IPForward=kernel

~ $ cat /etc/systemd/networkd.conf 
#  This file is part of systemd.
#
#  systemd is free software; you can redistribute it and/or modify it
#  under the terms of the GNU Lesser General Public License as published by
#  the Free Software Foundation; either version 2.1 of the License, or
#  (at your option) any later version.
#
# Entries in this file show the compile time defaults.
# You can change settings by editing this file.
# Defaults can be restored by simply deleting this file.
#
# See networkd.conf(5) for details

[Network]
#SpeedMeter=no
#SpeedMeterIntervalSec=10sec

[DHCP]
#DUIDType=vendor
#DUIDRawData=

if systemd-networkd is running, the ip address does not appear on the interface with yggdrasil, but connection to external peers occurs

[whoizit]

~ $ for x in iptables-legacy iptables-nft ebtables-nft arptables-nft; do echo "$x:"; sudo $x -L; echo; done
iptables-legacy:

Chain INPUT (policy ACCEPT)
target     prot opt source               destination         
Chain FORWARD (policy ACCEPT)
target     prot opt source               destination         
Chain OUTPUT (policy ACCEPT)
target     prot opt source               destination         

iptables-nft:

Chain INPUT (policy ACCEPT)
target     prot opt source               destination         
Chain FORWARD (policy ACCEPT)
target     prot opt source               destination         
Chain OUTPUT (policy ACCEPT)
target     prot opt source               destination         
# Warning: iptables-legacy tables present, use iptables-legacy to see them

ebtables-nft:

Bridge table: filter
Bridge chain: INPUT, entries: 0, policy: ACCEPT
Bridge chain: FORWARD, entries: 0, policy: ACCEPT
Bridge chain: OUTPUT, entries: 0, policy: ACCEPT

arptables-nft:

Chain INPUT (policy ACCEPT)
Chain OUTPUT (policy ACCEPT)

[ne-vlezay80]

Create /etc/systemd/network/tun0.network:|

[Match]
Name=tun0

[Address]
Address=<ygg_addr>/128

[Route]
Destination=200::/7

[neilalexander]

I am not really sure what the best way is to deal with this. I guess systemd-networkd is managing the adapter addresses and unsetting the address that we configure.

It’s difficult to add something into packages because it is basically impossible to predict the TUN adapter name that someone will want to use, or what will be automatically assigned on a given system if auto is used.

Immensely frustrating that the Linux community seem to consistently come up with bad solutions to problems that don’t really need solving further.

[whoizit]

this works for me

~ $ cat /etc/systemd/network/99-yggdrasil.network 
[Match]
Name=ygg

[Address]
Address=<ygg_ip>

[Route]
Destination=200::/7

[zhoreeq]

There must be a bug in systemd-networkd. It was also breaking my openvpn client.

Run networkctl status -a. It will show a "Network File" which is used to configure the interface. My system was using a config for wireless adapter, but for ygg0. I removed this config file and restarted systemd-networkd. Now it works.

If it doesn't, one could also create a network file to explicitly ignore those interfaces.

[Match]
Name=tun0 ygg0

[Link]
Unmanaged=yes