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Changes for page IPv6

Last modified by Sebastian Marsching on 2022/05/29 14:06
From version 1.2
edited by Sebastian Marsching
on 2022/05/29 13:29
Change comment: Added tag [Network]
To version 2.1
edited by Sebastian Marsching
on 2022/05/29 13:52
Change comment: Renamed back-links.

Summary

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Parent
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1 -Miscellaneous.Network.IP.WebHome
1 +Network.IP.WebHome
Content
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23 23  
24 24  With the default MTU setting of 1480 I experienced strange problems: Sometimes, connections got "stuck". By manually setting the MTU for the `tun6to4` interface to 1280 these problems could be solved. I guess, that these problem might be related to packet fragmentation when encapsulating the IPv6 packet within an IPv4 packet.
25 25  
26 -See also: [[Path MTU Discovery issues|doc:Miscellaneous.Network.IP.WebHome|anchor="HPathMTUDiscoveryIssues"]]
26 +See also: [[Path MTU Discovery issues|doc:Network.IP.WebHome|anchor="HPathMTUDiscoveryIssues"]]
27 27  
28 28  # IPv6 with Xen routed setup
29 29  
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89 89  1. Configuration gets easier: We do not have to create host routes, the routes will be automatically determined by the subnet prefix for the address. In the example
90 90  
91 91  above, a route for target `2002:ffff:ffff:1::/64` using the correct `vif`-device will be created automatically. There is also no need to manually configure a host-route to the gateway within the domU: The gateway's address (for `mydomu1` in the example it is `2002:ffff:ffff:1::1`) is within the subnet of the DomU.
92 +
92 92  1. We can easily add extra IP addresses to the DomU: As the Dom0 routes the whole subnet to the DomU, we can just add any address (except the gateway address) within
93 93  
94 94  the `/64` subnet to the DomU, without having to change any configuration within the Dom0.
96 +
95 95  1. The IPv6 address space is vast: If we have a `/48` subnet for the whole Xen host and we use a `/64` subnet for each DomU, we can create up to nearly 2^16 [DomUs](https://sebastian.marsching.com/wiki/DomUs) on one Xen host. These are more [DomUs](https://sebastian.marsching.com/wiki/DomUs) than you will ever run on a single Xen host.
96 96  
97 97  In order to make this setup work, we still have to ensure that the script `/etc/xen/scripts/vif-routed-ipv6` is called on the startup of a DomU. The easiest way is to patch `/etc/xen/scripts/vif-routed` using the following patch:
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317 317   mkdir -p "`dirname "${prefix_file}"`"
318 318   echo -n "${new_prefix}" >"${prefix_file}"
319 319  fi
320 -
321 321  ```
322 322  
323 323  In this script, you have to adjust your internally used prefix (when choosing a ULA prefix, you should use a random number from the range fc::/7 in order to avoid colissions when connecting different networks using addresses from the ULA space). Like in the other configuration files, you have to change the interface name from `eth0` to whichever is the name of the interface that connects to the Internet router.