[strongSwan] IPv6 Remote Access

Dusan Ilic dusan at comhem.se
Tue Jun 6 12:10:05 CEST 2017


Hello again,

It seems that the issue actually isn't with either Strongswan nor 
Android OS. If I'm connected by wifi locally to the LAN, IPv6 works 
great in every way, however when remotely using Stronswan Android client 
to connect IPv6 doesn't work in Google Chrome. First I thought it had 
something to do with DNS-assignment in Strongswan, but, when I try 
Firefox mobile IPv6 works. I have even ruled out IPv4 by creating a new, 
separate tunnel with only IPv6 assignment (and enabling block 
IPv4-traffic in Strongswan client) and IPv6 internet still work in 
Firefox, but not in Google Chrome (DNS-names). Also I can use other 
Android apps like ping and ping both IPv6 adresses directly and even 
domain names only having AAAA-records.

Any ideas or suggestios why it's behaving like this?


Den 2017-05-31 kl. 14:13, skrev Dusan Ilic:
> Okey, that's too bad. There isn't any workaround to make IPv6 DNS work 
> on Android Strongswan client? When pushing an IPv6 DNS Strongswan 
> iseem to fail to install any  DNSes, and just falls back to the 
> mobile/Wifis-networks configured DNS-servers.
>
>
> Den 2017-05-31 kl. 12:52, skrev Noel Kuntze:
>> I can access IPv6 here just fine and the IPv4 DNS traffic is NATed to 
>> my local DNS server on my VPN server,
>> but Android doesn't seem to be able to resolve any names, if I push 
>> just an IPv6 DNS server to it.
>> It also doesn't send any DNS requests over IPv6.
>>
>> I think this is likely a bug in Android, rather than in the 
>> strongSwan app.
>>
>> PS: Always send to the list, too (unless it's actually private)
>>
>> On 31.05.2017 10:01, Dusan Ilic wrote:
>>> I'm experiencing a new problem, somehow DNS is not working as it 
>>> should on IPv6.
>>> I can see in the Strongswan Android app log that both IPv4 and IPv6 
>>> DNS-servers are assigned, according to my configuration in 
>>> ipsec.conf (both are my Strongswan host), but only IPv4 hostnames 
>>> are resolved. I can ping IPv6 addresses only by IP, but cannot 
>>> access any domain with AAAA-record.
>>>
>>> I have tried replacing the IPv6 DNS-server with Googles public too, 
>>> but that doesn't make any difference.
>>> Even more strange, when assigning both DNS-servers it seems that the 
>>> Android client is using the 4G-providers DNS-servers instead (no 
>>> internal hostnames on the local DNS resolves), when removing the 
>>> IPv6 from rightdns it starts working again (however, no IPv6 
>>> resolving). Also only assigning IPv6 DNS-server doesn't work either.
>>>
>>>
>>>
>>> Could this be a bug?
>>>
>>>
>>> Den 2017-05-30 kl. 11:57, skrev Dusan Ilic:
>>>> Okey, I found the issue. The Linux kernel modules for IPsec IPv6 
>>>> were not loaded as I haven't used them before. Loaded them now and 
>>>> it works.
>>>>
>>>>
>>>> Den 2017-05-29 kl. 08:41, skrev dusan at comhem.se:
>>>>> Hi Noel,
>>>>>
>>>>> I have tried both command "ping" and "ping6". I can ping other 
>>>>> local hosts and external IPv6-adresses with "ping6".
>>>>> Unfortunately command "iptables6-save" and " sysctl -A | grep 
>>>>> net.ipv6.conf.*forwarding" doesn't work on my Linux router (not 
>>>>> found), but here are "ip6tables -L -v".
>>>>>
>>>>> # ip6tables -L -v
>>>>> Chain INPUT (policy DROP 0 packets, 0 bytes)
>>>>>    pkts bytes target     prot opt in     out source               
>>>>> destination
>>>>>       0     0 DROP       all      any    any anywhere             
>>>>> anywhere             rt type:0 segsleft:0
>>>>>      80 12467 ACCEPT     all      any    any anywhere             
>>>>> anywhere             state RELATED,ESTABLISHED
>>>>>       0     0 ACCEPT     ipv6-nonxt    any    any 
>>>>> anywhere             anywhere             length 40
>>>>>       0     0 shlimit    tcp      br0    any anywhere             
>>>>> anywhere             tcp dpt:ssh state NEW
>>>>> 14952 1175K ACCEPT     all      br0    any anywhere             
>>>>> anywhere
>>>>>       0     0 ACCEPT     all      lo     any anywhere             
>>>>> anywhere
>>>>>       0     0 logaccept  ipv6-icmp    any    any 
>>>>> anywhere             anywhere             ipv6-icmp 
>>>>> destination-unreachable
>>>>>       0     0 logaccept  ipv6-icmp    any    any 
>>>>> anywhere             anywhere             ipv6-icmp packet-too-big
>>>>>       0     0 logaccept  ipv6-icmp    any    any 
>>>>> anywhere             anywhere             ipv6-icmp time-exceeded
>>>>>       0     0 logaccept  ipv6-icmp    any    any 
>>>>> anywhere             anywhere             ipv6-icmp parameter-problem
>>>>>       0     0 logaccept  ipv6-icmp    any    any 
>>>>> anywhere             anywhere             ipv6-icmp echo-request
>>>>>       0     0 logaccept  ipv6-icmp    any    any 
>>>>> anywhere             anywhere             ipv6-icmp echo-reply
>>>>>     522 37584 logaccept  ipv6-icmp    any    any 
>>>>> anywhere             anywhere             ipv6-icmptype 130
>>>>>       0     0 logaccept  ipv6-icmp    any    any 
>>>>> anywhere             anywhere             ipv6-icmptype 131
>>>>>       0     0 logaccept  ipv6-icmp    any    any 
>>>>> anywhere             anywhere             ipv6-icmptype 132
>>>>>       0     0 logaccept  ipv6-icmp    any    any 
>>>>> anywhere             anywhere             ipv6-icmp 
>>>>> router-solicitation
>>>>>       0     0 logaccept  ipv6-icmp    any    any 
>>>>> anywhere             anywhere             ipv6-icmp 
>>>>> router-advertisement
>>>>>       0     0 logaccept  ipv6-icmp    any    any 
>>>>> anywhere             anywhere             ipv6-icmp 
>>>>> neighbour-solicitation
>>>>>       0     0 logaccept  ipv6-icmp    any    any 
>>>>> anywhere             anywhere             ipv6-icmp 
>>>>> neighbour-advertisement
>>>>>       0     0 logaccept  ipv6-icmp    any    any 
>>>>> anywhere             anywhere             ipv6-icmptype 141
>>>>>       0     0 logaccept  ipv6-icmp    any    any 
>>>>> anywhere             anywhere             ipv6-icmptype 142
>>>>>       0     0 logaccept  ipv6-icmp    any    any 
>>>>> anywhere             anywhere             ipv6-icmptype 143
>>>>>       0     0 logaccept  ipv6-icmp    any    any 
>>>>> anywhere             anywhere             ipv6-icmptype 148
>>>>>       0     0 logaccept  ipv6-icmp    any    any 
>>>>> anywhere             anywhere             ipv6-icmptype 149
>>>>>       0     0 logaccept  ipv6-icmp    any    any 
>>>>> anywhere             anywhere             ipv6-icmptype 151
>>>>>       0     0 logaccept  ipv6-icmp    any    any 
>>>>> anywhere             anywhere             ipv6-icmptype 152
>>>>>       0     0 logaccept  ipv6-icmp    any    any 
>>>>> anywhere             anywhere             ipv6-icmptype 153
>>>>>       0     0 logaccept  tcp      any    any anywhere             
>>>>> anywhere             tcp dpt:webcache
>>>>>
>>>>> Chain FORWARD (policy DROP 0 packets, 0 bytes)
>>>>>    pkts bytes target     prot opt in     out source               
>>>>> destination
>>>>>       0     0            all      vlan847 any 
>>>>> 2001:2002:5ae1:c206:5076:327e:xxx:xxx/128  anywhere
>>>>>       0     0 DROP       all      any    any anywhere             
>>>>> anywhere             rt type:0 segsleft:0
>>>>>       0     0 ACCEPT     all      br0    br0 anywhere             
>>>>> anywhere
>>>>>       0     0 ACCEPT     all      br1    br1 anywhere             
>>>>> anywhere
>>>>>       0     0 ACCEPT     all      br2    br2 anywhere             
>>>>> anywhere
>>>>>     410 21787 DROP       all      any    any anywhere             
>>>>> anywhere             state INVALID
>>>>>    154K   98M ACCEPT     all      any    any anywhere             
>>>>> anywhere             state RELATED,ESTABLISHED
>>>>>       0     0 DROP       all      6rd    6rd anywhere             
>>>>> anywhere
>>>>>       0     0 ACCEPT     ipv6-nonxt    any    any 
>>>>> anywhere             anywhere             length 40
>>>>>       0     0 logaccept  ipv6-icmp    any    any 
>>>>> anywhere             anywhere             ipv6-icmp 
>>>>> destination-unreachable
>>>>>       0     0 logaccept  ipv6-icmp    any    any 
>>>>> anywhere             anywhere             ipv6-icmp packet-too-big
>>>>>       0     0 logaccept  ipv6-icmp    any    any 
>>>>> anywhere             anywhere             ipv6-icmp time-exceeded
>>>>>       0     0 logaccept  ipv6-icmp    any    any 
>>>>> anywhere             anywhere             ipv6-icmp parameter-problem
>>>>>    4620  241K logaccept  ipv6-icmp    any    any 
>>>>> anywhere             anywhere             ipv6-icmp echo-request
>>>>>       0     0 logaccept  ipv6-icmp    any    any 
>>>>> anywhere             anywhere             ipv6-icmp echo-reply
>>>>>       0     0 ACCEPT     ipv6-crypt    6rd    any 
>>>>> anywhere             anywhere
>>>>>       0     0 ACCEPT     udp      6rd    any anywhere             
>>>>> anywhere             udp dpt:500
>>>>>    6246 1012K wanin      all      6rd    any anywhere             
>>>>> anywhere
>>>>>    5040  646K wanout     all      any    6rd anywhere             
>>>>> anywhere
>>>>>    5040  646K ACCEPT     all      br0    any anywhere             
>>>>> anywhere
>>>>>       0     0 ACCEPT     all      br1    any anywhere             
>>>>> anywhere
>>>>>       0     0 ACCEPT     all      br2    any anywhere             
>>>>> anywhere
>>>>>       0     0 ACCEPT     all      br0    6rd anywhere             
>>>>> anywhere
>>>>>       0     0 ACCEPT     all      br1    6rd anywhere             
>>>>> anywhere
>>>>>       0     0 ACCEPT     all      br2    6rd anywhere             
>>>>> anywhere
>>>>>
>>>>> Chain OUTPUT (policy ACCEPT 3 packets, 363 bytes)
>>>>>    pkts bytes target     prot opt in     out source               
>>>>> destination
>>>>>       0     0 DROP       all      any    any anywhere             
>>>>> anywhere             rt type:0 segsleft:0
>>>>>
>>>>> Chain logaccept (30 references)
>>>>>    pkts bytes target     prot opt in     out source               
>>>>> destination
>>>>>    4769  253K LOG        all      any    any anywhere             
>>>>> anywhere             state NEW limit: avg 1/sec burst 5 LOG level 
>>>>> warning tcp-sequence tcp-options ip-options macdecode prefix 
>>>>> "ACCEPT "
>>>>>    5306  292K ACCEPT     all      any    any anywhere             
>>>>> anywhere
>>>>>
>>>>> Chain logdrop (0 references)
>>>>>    pkts bytes target     prot opt in     out source               
>>>>> destination
>>>>>       0     0 LOG        all      any    any anywhere             
>>>>> anywhere             state NEW limit: avg 1/sec burst 5 LOG level 
>>>>> warning tcp-sequence tcp-options ip-options macdecode prefix "DROP "
>>>>>       0     0 DROP       all      any    any anywhere             
>>>>> anywhere
>>>>>
>>>>> Chain logreject (0 references)
>>>>>    pkts bytes target     prot opt in     out source               
>>>>> destination
>>>>>       0     0 LOG        all      any    any anywhere             
>>>>> anywhere             limit: avg 1/sec burst 5 LOG level warning 
>>>>> tcp-sequence tcp-options ip-options macdecode prefix "REJECT "
>>>>>       0     0 REJECT     tcp      any    any anywhere             
>>>>> anywhere             reject-with tcp-reset
>>>>>
>>>>> Chain shlimit (1 references)
>>>>>    pkts bytes target     prot opt in     out source               
>>>>> destination
>>>>>       0     0            all      any    any anywhere             
>>>>> anywhere             recent: SET name: shlimit side: source
>>>>>       0     0 DROP       all      any    any anywhere             
>>>>> anywhere             recent: UPDATE seconds: 60 hit_count: 4 name: 
>>>>> shlimit side: source
>>>>>
>>>>> Chain wanin (1 references)
>>>>>    pkts bytes target     prot opt in     out source               
>>>>> destination
>>>>>
>>>>> Chain wanout (1 references)
>>>>>    pkts bytes target     prot opt in     out source               
>>>>> destination
>>>>>
>>>>> # ipsec statusall vpn-ipv6
>>>>> Status of IKE charon daemon (strongSwan 5.5.1, Linux 
>>>>> 2.6.36.4brcmarm, armv7l):
>>>>>     uptime: 11 hours, since May 28 18:35:50 2017
>>>>>     malloc: sbrk 831488, mmap 0, used 416048, free 415440
>>>>>     worker threads: 10 of 16 idle, 6/0/0/0 working, job queue: 
>>>>> 0/0/0/0, scheduled: 13
>>>>>     loaded plugins: charon test-vectors ldap pkcs11 aes des 
>>>>> blowfish rc2 sha2 sha1 md4 md5 random nonce x509 revocation 
>>>>> constraints pubkey pkcs1 pkcs8 pgp dnskey sshkey pem openssl 
>>>>> gcrypt fips-prf gmp gmpdh agent xcbc cmac hmac ctr ccm gcm curl 
>>>>> mysql sqlite attr kernel-netlink resolve socket-default 
>>>>> socket-dynamic farp stroke smp updown eap-identity eap-md5 
>>>>> eap-mschapv2 eap-radius xauth-generic xauth-eap dhcp whitelist led 
>>>>> duplicheck addrblock unity
>>>>> Listening IP addresses:
>>>>>     85.24.xx.xx
>>>>>     2001:2002:5ae1:xxx::xx
>>>>> Connections:
>>>>>       vpn-ipv6:  %any...%any  IKEv2, dpddelay=300s
>>>>>       vpn-ipv6:   local:  [vpn.joksi.net] uses public key 
>>>>> authentication
>>>>>       vpn-ipv6:   remote: uses EAP_MSCHAPV2 authentication with 
>>>>> EAP identity 'dulemis3'
>>>>>       vpn-ipv6:   child:  2000::/3 === dynamic TUNNEL, 
>>>>> dpdaction=clear
>>>>> Security Associations (4 up, 0 connecting):
>>>>>       vpn-ipv6[26]: ESTABLISHED 2 minutes ago, 
>>>>> 85.24.xx.xx[x]...94.234.xx.xx[x]
>>>>>       vpn-ipv6[26]: IKEv2 SPIs: a7ac5d658a4a39ac_i 
>>>>> 278aaa324f402aaa_r*, public key reauthentication in 2 hours
>>>>>       vpn-ipv6[26]: IKE proposal: 
>>>>> AES_CBC_128/HMAC_SHA1_96/PRF_HMAC_SHA1/MODP_3072
>>>>>       vpn-ipv6{1622}:  INSTALLED, TUNNEL, reqid 6, ESP in UDP 
>>>>> SPIs: c9edd06c_i 66f8c36e_o
>>>>>       vpn-ipv6{1622}:  AES_CBC_128/HMAC_SHA2_256_128, 11600 
>>>>> bytes_i, 0 bytes_o, rekeying in 39 minutes
>>>>>       vpn-ipv6{1622}:   2000::/3 === 
>>>>> 2001:2002:5ae1:c206:5076:327e:xx:xx/128
>>>>>
>>>>> conn vpn-ikev2
>>>>>           auto=add
>>>>>           reauth=yes
>>>>>           dpdaction=clear
>>>>>           dpddelay=300s
>>>>>           mobike=yes
>>>>>
>>>>>           leftid=xxx
>>>>>           leftsubnet=0.0.0.0/0,2000::/3
>>>>>           leftauth=pubkey
>>>>>
>>>>>           right=%any
>>>>>           rightsubnet=%dynamic
>>>>> rightsourceip=%dhcp,2001:2002:5ae1:c206:5076:327e:xxx:xxx
>>>>>           rightauth=eap-mschapv2
>>>>>
>>>>>           eap_identity=%any
>>>>>
>>>>>> ----Ursprungligt meddelande----
>>>>>> Från : noel.kuntze+strongswan-users-ml at thermi.consulting
>>>>>> Datum : 29/05/2017 - 00:16 (V)
>>>>>> Till : dusan at comhem.se, users at lists.strongswan.org
>>>>>> Ämne : Re: [strongSwan] IPv6 Remote Access
>>>>>>
>>>>>> Hello Dusan,
>>>>>>
>>>>>> On 28.05.2017 19:24, Dusan Ilic wrote:
>>>>>>> Hi Noel,
>>>>>>>
>>>>>>> The IPv6 prefix is on link so I've tried adding static NDP 
>>>>>>> record, when pinging from a local host before adding the static 
>>>>>>> record it says "destination host unreacable", but after adding 
>>>>>>> it it says "request timed out".
>>>>>>>
>>>>>>> When i try pinging the client from the strongswan host i get the 
>>>>>>> following error?
>>>>>>> ping6: sendto: Address family not supported by protocol
>>>>>> What command are you trying to use?
>>>>>>
>>>>>>> Strongswan now added a route for the IPv6 adress out the correct 
>>>>>>> WAN-interface, and I have added an input and forward rule in 
>>>>>>> ip6tables accepting traffic. I can see in "ipsec statusall" that 
>>>>>>> the incoming packet counter are increasing, but not the outgoing.
>>>>>> Provide `ip6tables-save`, your ipsec.conf, `ipsec statusall` and  
>>>>>> `sysctl -A | grep net.ipv6.conf.*forwarding`.
>>>>>>
>>>>>> Kind regards
>>>>>>
>>>>>> Noel
>>>>>>
>>>>>>> Den 2017-05-26 kl. 17:47, skrev Noel Kuntze:
>>>>>>>> Hello Dusan,
>>>>>>>>
>>>>>>>> On 26.05.2017 16:52, Dusan Ilic wrote:
>>>>>>>>> Hi everyone,
>>>>>>>>>
>>>>>>>>> My ISP have just recently enabled IPv6 in their network (well, 
>>>>>>>>> 6RD aactually) and I have it confiogured and working at the site.
>>>>>>>>> I would now also like to enable it on my remote access VPN in 
>>>>>>>>> Strongswan too, so I made a try with the following config 
>>>>>>>>> however it doesnt seem work. According to Strongswan log the 
>>>>>>>>> client asks for ipv6 (Android in this case) and get's assigned 
>>>>>>>>> one (global from my public prefix).
>>>>>>>>>
>>>>>>>>> leftsubnet=0.0.0.0/0,2000::/3 (also tried with ::/0)
>>>>>>>>> rightsourceip=%dhcp,2001:2002:5ae1:c206:4466:d122:xxx:xxx
>>>>>>>>>
>>>>>>>>> This is a test, so that's why Im only assigning one single 
>>>>>>>>> IPv6 adress for the time being. IPv4 works as expected, but I 
>>>>>>>>> can't neither reach an IPv6 internet site nor ping the gateway 
>>>>>>>>> or the Android client from the gateway/clients behind the 
>>>>>>>>> gateway.
>>>>>>>> Check if the IPv6 packets make it to the strongSwan host. And 
>>>>>>>> then make sure those IPv6 addresses are routed over the 
>>>>>>>> strongSwan host. If the subnet they're from is on the link,
>>>>>>>> you'll need to create do proxy NDP on the strongSwan host with 
>>>>>>>> either static records in the NDP table on the strongSwan host 
>>>>>>>> or by using and configuring ndppd[1] on the strongSwan host.
>>>>>>>>> What I'm reacting on is that a route gets created for the IPv4 
>>>>>>>>> adress in my routing table, but none for the IPv6 adress. Also 
>>>>>>>>> checked with "ip -6 route".
>>>>>>>>> Is this a routing problem possibly, or maybe an firewall 
>>>>>>>>> (iptables) problem?
>>>>>>>> The latter maybe. IPv6 traffic goes through ip6tables, not 
>>>>>>>> iptables.
>>>>>>>>
>>>>>>>>> Just to be clear, the client is connecting to the Strongswan 
>>>>>>>>> server with IPv4, should receive an IPv6 global adress inside 
>>>>>>>>> the tunnel and then my Strongswan server should route it out 
>>>>>>>>> on the internet (through the 6RD-tunnel).
>>>>>>>>>
>>>>>>>> Read the FAQ[2], too.
>>>>>>>>
>>>>>>>> Kind regards
>>>>>>>>
>>>>>>>> Noel
>>>>>>>>
>>>>>>>> [1] https://github.com/DanielAdolfsson/ndppd
>>>>>>>> [2] 
>>>>>>>> https://wiki.strongswan.org/projects/strongswan/wiki/FAQ#IPsec-and-iptablesnftables
>>>>>>>>
>>>>>>>>
>>>>>>>>
>



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