Major problem with DHCPv6 static mappings
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@jknott said in Major problem with DHCPv6 static mappings:
Also, do you need DHCPv6? Android devices won't work with it. You can thank some "genius" at Google for that one.
What do you mean by that?
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@chrisjenk said in Major problem with DHCPv6 static mappings:
That's fine if there is only ever one interface active on the host at any time, but this is rarely the case.
Is it though? I would say it is the overwhelming case.
But you are right, if you got two on the same network, then DHCPv6 is only working for one. -
@bob-dig As I explained, it isn't the overwhelming case at all in some scenarios; here at home for example it is the common case. Probably less so in a more enterprisey setup. Also, even in this case DHCPv6 works fine unless you use static mappings. Sadly, I really want to use static mappings for a segment of my client population.
This is clearly a deficiency in pfSense DHCPv6 support (one might call it a bug).
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@bob-dig said in Major problem with DHCPv6 static mappings:
What do you mean by that?
Android devices don't support DHCPv6. This was a decision by someone on the Android team at Google.
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Don’t most operating systems disable wifi if ethernet is enabled and on the same subnet.
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@jknott said in Major problem with DHCPv6 static mappings:
Android devices don't support DHCPv6. This was a decision by someone on the Android team at Google.
You're right. Should have my phone checked first.
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@nogbadthebad If by 'most' you mean Windows then yes (so I am informed). Neither Linux nor macOS do so however. There is no reason to do so after all (unless your DHCP server has incorrectly handed out the same IP address to both interfaces!).
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@nogbadthebad said in Major problem with DHCPv6 static mappings:
Don’t most operating systems disable wifi if ethernet is enabled and on the same subnet.
No, *nix use "metric" to decide. The lowest metric is selected. For example, my ThinkPad is connected via both Ethernet and WiFi to my LAN. Here's what it shows:
ip route show
default via 172.16.0.1 dev eth0 proto dhcp metric 100
default via 172.16.0.1 dev wlan0 proto dhcp metric 600
172.16.0.0/24 dev eth0 proto kernel scope link src 172.16.0.42 metric 100
172.16.0.0/24 dev wlan0 proto kernel scope link src 172.16.0.40 metric 600Since Ethernet has a 100 metric and WiFi 600, Ethernet will be used.
This is basic routing and all the routing protocols use a metric for the the routes to pick the best one. For example, the obsolete Routing Information Protocol (RIP) used hop count. So a single hop would have a lower metric than a 2 hop route and be selected. More sophisticated routing protocols, such as OSPF or EIGRP use more advanced metrics that can also include things like bandwidth and more.
A bit of history, IP was created on BSD Unix, at University of California, Berkeley and the Internet is pretty much built on various Unix, including Linux, variants and even Cisco has used Unix or Linux in routers.
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A bit of history, IP was created on BSD Unix, at University of California, Berkeley and the Internet is pretty much built on various Unix, including Linux, variants and even Cisco has used Unix or Linux in routers.
Yup I’m old enough to remember installing the Unipalm TCP IP stack onto DOS PCs as well as Windows.
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I never had occasion to use IP on DOS. Back in those days, we had Netware at work and I recall modifying config.sys and autoexec.bat to run it. NET3 & NETX come to mind. I didn't deal with IP until I got my own connection and was running OS/2. Then, at IBM, I worked with IP, SNA and NetBIOS on token ring.