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Old 09-07-2015, 06:16 AM   #1
dr.x
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Linux IPV6 routing issue with 2 interfaces


Hi
i have centos server with eth0 interfaces and lo default loopback .

now i have the subnet of 2a06:1280:bee1::3/64 on eth0
now if i ping 2a06:1280:bee1::3 from anywhere , i can reach it .

now assume i add other address like :
ip addr add 2a06:1280:bee1::aaaa/64 dev eth0
ip addr add 2a06:1280:bee1::bbbb/64 dev eth0

then the ips 2a06:1280:bee1::aaaa & 2a06:1280:bee1::bbbb are pingable .

but i have a problem .

say i have other GRE interface that had tunnel ip6-4 with other server.

if i put any ip from my subnet to the tunnel interface .
it never reach it.

as an example
if i have gre tunnle :
ip tunnel add IPV61 mode sit remote 67.212.83.32 local 185.99.132.3 ttl 255
ip link set IPV61 up
ip addr add 2a06:1280:bee1:1000::1/64 dev IPV61

as we see i cant ping that interface !!!

but if i put the ip of that tunnel to eth0 it works !!!

so i think im here with a problem with routing or interfaces sharing .

seems like ping works & connectiviy to outside world works only if i out it on eth0 .

any help ??

============================================
[root@rns ~]# cat /etc/sysctl.conf
# Kernel sysctl configuration file for Red Hat Linux
#
# For binary values, 0 is disabled, 1 is enabled. See sysctl(8) and
# sysctl.conf(5) for more details.

# Controls IP packet forwarding
net.ipv4.ip_forward = 1
net.ipv4.conf.all.forwarding=1
net.ipv4.conf.default.forwarding=1

net.ipv6.conf.default.forwarding = 1
net.ipv6.conf.all.forwarding=1
net.ipv6.conf.default.forwarding=1
# Controls source route verification
net.ipv4.conf.default.rp_filter = 1

# Do not accept source routing
net.ipv4.conf.default.accept_source_route = 0

# Controls the System Request debugging functionality of the kernel
kernel.sysrq = 0

# Controls whether core dumps will append the PID to the core filename.
# Useful for debugging multi-threaded applications.
kernel.core_uses_pid = 1

# Controls the use of TCP syncookies
net.ipv4.tcp_syncookies = 1

# Controls the default maxmimum size of a mesage queue
kernel.msgmnb = 65536

# Controls the maximum size of a message, in bytes
kernel.msgmax = 65536

# Controls the maximum shared segment size, in bytes
kernel.shmmax = 68719476736

# Controls the maximum number of shared memory segments, in pages
kernel.shmall = 4294967296
###################
net.ipv6.conf.all.forwarding = 1
net.ipv6.conf.eth0.accept_ra = 1
net.ipv6.conf.eth0.accept_ra_defrtr = 1
net.ipv6.conf.eth0.router_solicitations = 1
#########################
net.ipv6.conf.all.forwarding = 1
net.ipv6.conf.IPV61.accept_ra = 1
net.ipv6.conf.IPV61.accept_ra_defrtr = 1
net.ipv6.conf.IPV61.router_solicitations = 1
[root@rns ~]# cat /etc/sysconfig/network-scripts/ifcfg-eth0
DEVICE=eth0
TYPE=Ethernet
UUID=173ca404-2018-4594-98c5-8ab349875a78
ONBOOT=yes
NM_CONTROLLED=yes
BOOTPROTO=none
IPADDR=xxx
PREFIX=24
GATEWAY=xxx
DNS1=8.8.8.8
DOMAIN="search.local dns.local"
DEFROUTE=yes
IPV4_FAILURE_FATAL=yes
IPV6INIT=yes
NAME="System eth0"
IPV6_AUTOCONF=no
IPV6_DEFAULTGW=2a06:1280:bee1::dea:1
IPV6ADDR=2a06:1280:bee1::3/64
IPV6_DEFROUTE=yes
IPV6_FAILURE_FATAL=yes
HWADDR=D2:80:52:9A:79:AB
DNS2=2001:4860:4860::8888
LAST_CONNECT=1441361689
NETWORKING_IPV6=yes
[root@rns ~]#


cat /etc/sysconfig/network
NETWORKING=yes
HOSTNAME=rns.nz1.zappiehost.com
GATEWAY=xxxx
IPV6_DEFAULTGW=2a06:1280:bee1::dea:1
NETWORKING_IPV6=yes



any help ???
 
Old 09-08-2015, 02:31 PM   #2
nini09
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Where are two GRE terminators, on server?
 
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Old 09-09-2015, 04:42 AM   #3
dr.x
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yes on same server .

the question is , why only the ip ping-able and able to reach internet only if it was on eth0 ???

i want to ask , do i need other ting to be enabled ?

i believe this is normal routing issue and shroud be enabled by default , but dont know why ...any help ?

thankx
 
Old 09-09-2015, 02:28 PM   #4
nini09
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GRE tunnel interface should be over a physical interface, shouldn't it? Otherwise, how can packet go to wire?
 
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Old 09-09-2015, 03:38 PM   #5
dr.x
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yes u r correct ,
but if i add IPV6 address to that GR tunnel , whey i cant ping it ?

but same ip of i put it on the physical (eth0)
i can ping it

do u have any explanation for that ?
 
Old 09-10-2015, 09:41 AM   #6
dr.x
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can u help me wt does this trace mean ??
traceroute6 2602:ffd5:1:100::1
traceroute to 2602:ffd5:1:100::1 (2602:ffd5:1:100::1), 30 hops max, 80 byte packets
1 2602:ffd5:1:dddd:bbbb::1 (2602:ffd5:1:dddd:bbbb::1) 18.209 ms !N 18.108 ms !N 18.082 ms !N
root@ca:~#


when it die at that host ?
 
Old 09-10-2015, 02:43 PM   #7
nini09
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If there is IPv6 and IPv4 conversion, two physical interfaces are requested, one connect to IPv4 and another connect to IPv6.
You can use GRE tunnel encapsulate IPv4 packet over IPv6 network.
 
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Old 09-10-2015, 04:26 PM   #8
dr.x
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ok , let me discuss my issue for you shortly and let me explain the issue i have .
i will post full topology shortly of wt i want to do

thanks
 
Old 09-10-2015, 05:15 PM   #9
dr.x
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Hi ,
i have linux server that already contacin ipv6 address/64 and able to reach ipv6 destination without any problem.

but i want to cut some ips of that main server and give it to other server by tunnel so that other server be able to reach ipv6 websites .

i was able to do the tunnel between them and ping all the networks/ips between them.
my main problem is , the remote server that has some ips cutted from the /64 and put in it as /128 , is unable to reach internet .
and seems like the traceroute die on the main server and dont exit it .
hope you can help me .
let me explain what i did so far :
====================
server1-which is the main server has :
inet addr:162.250.189.177
inet6 addr: 2602:ffd5:1:112:999::1/64 Scope:Global
we can say 2602:ffd5:1:112::/64 subnet
==========================

server2-which is the remote server that will use the main server as ipv6 gateway has :
67.212.83.32
==========================

here below i will post the settings i useed for tunnel :

server1-main one :
ip tunnel add IPV6 mode sit remote 67.212.83.32 local 162.250.189.177 ttl 255
ip link set IPV6 up
ifconfig IPV6 inet add 2602:ffd5:1:dddd:bbbb::1/64
ip route add 2602:ffd5:1:112:112::/80 dev IPV6

server2-client one :
ip tunnel add IPV6 mode sit remote 162.250.189.177 local 67.212.83.32 ttl 255
ip link set IPV6 up
ip route add ::/0 dev IPV6
ifconfig IPV6 inet add 2602:ffd5:1:dddd:bbbb::2/64
ifconfig lo inet add 2602:ffd5:1:112:112::aaa/128

=======================

as we see above we have the tunnel point-point subnet as 2602:ffd5:1:dddd:bbbb::0/64
and i cut the ip from /64 to be 2602:ffd5:1:112:112::aaa/128 on the remte server so that it go with it the internet
and i let the clietn to use the main server as default gateway.
=============
ping between two servers all working :

1-ping from the main to client server :
[root@localhost ~]# ping6 2602:ffd5:1:dddd:bbbb::2
PING 2602:ffd5:1:dddd:bbbb::2(2602:ffd5:1:dddd:bbbb::2) 56 data bytes
64 bytes from 2602:ffd5:1:dddd:bbbb::2: icmp_seq=1 ttl=64 time=1.50 ms
64 bytes from 2602:ffd5:1:dddd:bbbb::2: icmp_seq=2 ttl=64 time=0.886 ms
^C
--- 2602:ffd5:1:dddd:bbbb::2 ping statistics ---
2 packets transmitted, 2 received, 0 packet loss, time 1454ms
rtt min/avg/max/mdev = 0.886/1.193/1.501/0.309 ms
[root@localhost ~]# ping6 2602:ffd5:1:dddd:bbbb::1
PING 2602:ffd5:1:dddd:bbbb::1(2602:ffd5:1:dddd:bbbb::1) 56 data bytes
64 bytes from 2602:ffd5:1:dddd:bbbb::1: icmp_seq=1 ttl=64 time=0.056 ms
64 bytes from 2602:ffd5:1:dddd:bbbb::1: icmp_seq=2 ttl=64 time=0.087 ms
^C
--- 2602:ffd5:1:dddd:bbbb::1 ping statistics ---
2 packets transmitted, 2 received, 0% packet loss, time 1512ms
rtt min/avg/max/mdev = 0.056/0.071/0.087/0.017 ms
[root@localhost ~]# ping6 2602:ffd5:1:112:112::aaa
PING 2602:ffd5:1:112:112::aaa(2602:ffd5:1:112:112::aaa) 56 data bytes
64 bytes from 2602:ffd5:1:112:112::aaa: icmp_seq=1 ttl=64 time=1.58 ms
64 bytes from 2602:ffd5:1:112:112::aaa: icmp_seq=2 ttl=64 time=1.02 ms
^C
--- 2602:ffd5:1:112:112::aaa ping statistics ---
2 packets transmitted, 2 received, 0% packet loss, time 1750ms
rtt min/avg/max/mdev = 1.023/1.303/1.583/0.280 ms
[root@localhost ~]# ping6 google.com -n
PING google.com(2607:f8b0:4006:80c::1000) 56 data bytes
64 bytes from 2607:f8b0:4006:80c::1000: icmp_seq=1 ttl=58 time=20.1 ms
64 bytes from 2607:f8b0:4006:80c::1000: icmp_seq=2 ttl=58 time=19.4 ms
^C
--- google.com ping statistics ---
2 packets transmitted, 2 received, 0% packet loss, time 1507ms
rtt min/avg/max/mdev = 19.420/19.776/20.133/0.383 ms
[root@localhost ~]#


as we see , server main is able to reach all ips on server2 and reach internet
====================
2-ping from server 2

root@ca:~# ping6 2602:ffd5:1:dddd:bbbb::2
PING 2602:ffd5:1:dddd:bbbb::2(2602:ffd5:1:dddd:bbbb::2) 56 data bytes
64 bytes from 2602:ffd5:1:dddd:bbbb::2: icmp_seq=1 ttl=64 time=0.027 ms
^C
--- 2602:ffd5:1:dddd:bbbb::2 ping statistics ---
1 packets transmitted, 1 received, 0% packet loss, time 0ms
rtt min/avg/max/mdev = 0.027/0.027/0.027/0.000 ms
root@ca:~# ping6 2602:ffd5:1:dddd:bbbb::1
PING 2602:ffd5:1:dddd:bbbb::1(2602:ffd5:1:dddd:bbbb::1) 56 data bytes
64 bytes from 2602:ffd5:1:dddd:bbbb::1: icmp_seq=1 ttl=64 time=1.40 ms
^C
--- 2602:ffd5:1:dddd:bbbb::1 ping statistics ---
1 packets transmitted, 1 received, 0% packet loss, time 0ms
rtt min/avg/max/mdev = 1.409/1.409/1.409/0.000 ms
root@ca:~# ping6 google.com -n
PING google.com(2607:f8b0:400d:c06::71) 56 data bytes




^C
--- google.com ping statistics ---
13 packets transmitted, 0 received, 100% packet loss, time 12095ms

root@ca:~# traceroute6 google.com
traceroute to google.com (2607:f8b0:400d:c06::8b), 30 hops max, 80 byte packets
1 * * *
2 * * *
3 * * *
4 * * *
5 * * *
6 *


root@ca:~# ip -6 route show
unreachable 2602:ffd5:1:112:112::aaa dev lo proto kernel metric 256 error -101
2602:ffd5:1:dddd::/64 dev IPV6 proto kernel metric 256
fe80::/64 dev eth0 proto kernel metric 256
fe80::/64 dev IPV6 proto kernel metric 256
default dev IPV6 metric 1024
root@ca:~#


agian the gateway of the client is the main , server , but it cant exit the maon sever to internet

where could be possible my mistake ???

note that all ipv4,ipv6 & selinux are disabled on both servers.

cheers
 
Old 09-11-2015, 03:17 PM   #10
nini09
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What's ip route output for IPv4 and IPv6 on server1-main?
What's eth0 IPv4 and IPv6 address setting on server2-client?

Last edited by nini09; 09-11-2015 at 03:23 PM.
 
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Old 09-11-2015, 03:47 PM   #11
dr.x
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main server side :

[main-server ~]# ip route show
10.8.0.2 dev tun0 proto kernel scope link src 10.8.0.1
10.8.0.0/24 via 10.8.0.2 dev tun0
162.250.189.0/24 dev eth0 proto kernel scope link src 162.250.189.177
192.169.1.0/24 dev tap_vpn1 proto kernel scope link src 192.169.1.1
169.254.0.0/16 dev eth0 scope link metric 1002
default via 162.250.189.1 dev eth0


[main-server ~]# ip -6 route show
unreachable ::/96 dev lo metric 1024 error -101 mtu 16436 advmss 16376 hoplimit 4294967295
unreachable ::ffff:0.0.0.0/96 dev lo metric 1024 error -101 mtu 16436 advmss 16376 hoplimit 4294967295
unreachable 2002:a00::/24 dev lo metric 1024 error -101 mtu 16436 advmss 16376 hoplimit 4294967295
unreachable 2002:7f00::/24 dev lo metric 1024 error -101 mtu 16436 advmss 16376 hoplimit 4294967295
unreachable 2002:a9fe::/32 dev lo metric 1024 error -101 mtu 16436 advmss 16376 hoplimit 4294967295
unreachable 2002:ac10::/28 dev lo metric 1024 error -101 mtu 16436 advmss 16376 hoplimit 4294967295
unreachable 2002:c0a8::/32 dev lo metric 1024 error -101 mtu 16436 advmss 16376 hoplimit 4294967295
unreachable 2002:e000::/19 dev lo metric 1024 error -101 mtu 16436 advmss 16376 hoplimit 4294967295
2602:ffd5:1:112:112::/80 dev IPV6 metric 1024 mtu 1480 advmss 1420 hoplimit 4294967295
2602:ffd5:1:112::/64 dev eth0 proto kernel metric 256 mtu 1500 advmss 1440 hoplimit 4294967295
2602:ffd5:1:dddd::/64 via :: dev IPV6 proto kernel metric 256 mtu 1480 advmss 1420 hoplimit 4294967295
2602:ffd5:1::/48 dev eth0 proto kernel metric 256 expires 0sec mtu 1500 advmss 1440 hoplimit 4294967295
unreachable 3ffe:ffff::/32 dev lo metric 1024 error -101 mtu 16436 advmss 16376 hoplimit 4294967295
fe80::/64 dev eth0 proto kernel metric 256 mtu 1500 advmss 1440 hoplimit 4294967295
fe80::/64 via :: dev IPV6 proto kernel metric 256 mtu 1480 advmss 1420 hoplimit 4294967295
default via fe80::768e:f8ff:fe61:e241 dev eth0 proto kernel metric 1024 expires 0sec mtu 1500 advmss 1440 hoplimit 64
[main-server ~]#



client side :

client]~# ~# ifconfig
IPV6 Link encap:IPv6-in-IPv4
inet6 addr: 2602:ffd5:1:dddd:bbbb::2/64 Scope:Global
inet6 addr: fe80::43d4:5320/64 Scope:Link
UP POINTOPOINT RUNNING NOARP MTU:1480 Metric:1
RX packets:8 errors:0 dropped:0 overruns:0 frame:0
TX packets:90 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:0
RX bytes:832 (832.0 B) TX bytes:7752 (7.5 KiB)

eth0 Link encap:Ethernet HWaddr 00:16:3e:b0:97:25
inet addr:67.212.83.32 Bcast:67.212.83.63 Mask:255.255.255.192
inet6 addr: fe80::216:3eff:feb0:9725/64 Scope:Link
UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1
RX packets:156855170 errors:0 dropped:0 overruns:0 frame:0
TX packets:93980727 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:1000
RX bytes:133424391804 (124.2 GiB) TX bytes:131559112024 (122.5 GiB)

lo Link encap:Local Loopback
inet addr:127.0.0.1 Mask:255.0.0.0
inet6 addr: ::1/128 Scope:Host
inet6 addr: 2602:ffd5:1:112:112::aaa/128 Scope:Global
UP LOOPBACK RUNNING MTU:65536 Metric:1
RX packets:2734 errors:0 dropped:0 overruns:0 frame:0
TX packets:2734 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:0
RX bytes:254379 (248.4 KiB) TX bytes:254379 (248.4 KiB)

client]~#
 
Old 09-12-2015, 03:17 PM   #12
dr.x
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any help ?
 
Old 09-14-2015, 02:29 PM   #13
nini09
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IPv6 default route is missed.
 
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Old 09-14-2015, 03:59 PM   #14
dr.x
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here is the default route from the client :

root@ca:~# ip -6 route show
unreachable 2602:ffd5:1:112:112::aaa dev lo proto kernel metric 256 error -101
2602:ffd5:1:dddd::/64 dev IPV6 proto kernel metric 256
fe80::/64 dev eth0 proto kernel metric 256
fe80::/64 dev IPV6 proto kernel metric 256
default dev IPV6 metric 1024
root@ca:~#
 
Old 09-14-2015, 04:07 PM   #15
dr.x
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and here is internet from the server to google :
ping6 google.com
PING google.com(lga15s48-in-x02.1e100.net) 56 data bytes
64 bytes from lga15s48-in-x02.1e100.net: icmp_seq=1 ttl=58 time=8.62 ms
64 bytes from lga15s48-in-x02.1e100.net: icmp_seq=2 ttl=58 time=8.29 ms
^C
--- google.com ping statistics ---
2 packets transmitted, 2 received, 0 packet loss, time 1510ms
rtt min/avg/max/mdev = 8.295/8.460/8.626/0.189 ms
[root@localhost ~]# tracepath6 -n google.com
1?: [LOCALHOST] pmtu 1500
1: 2602:ffd5:1:100::1 1.053ms
1: 2602:ffd5:1:100::1 0.250ms
2: 2001:590::451f:8e41 1.519ms asymm 3
3: 2001:668:0:2::1:1bb2 15.483ms











agian let me say agian :
ping from sever to anythung is 100 % ok
ping between server and client in ipv6 is 100 %
ping between client to server in ipv6 is 100 %

the problem is when the client try to reach the internet


any help ?
 
  


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