Not a scientist. I have a litany of complex topics that I just can’t really talk to anyone about. I’m a big computer networking nerd, and once upon a time, when I didn’t know what I didn’t know, I was curious what computer networking really entailed… It seemed dead simple, you connect things to a switch, connect that switch to the internet router, not much more.
Then I learned about VLANs, which are cool but it seemed like unnecessary complexity. Then I learned about Routing and L3 switching, and routing protocols and… Holy shit, how deep is this?
Now-a-days, I want to have conversations about the merits of one routing protocol over another in various contexts, and see/build a spine and leaf network infrastructure that’s nearly infinitely scalable.
I want to explore the nuance of IP unnumbered routing. I can’t find anyone who will chat about it on a level that’s close to my understanding, either someone knows way more than I do, or they know way less.
IP unnumbered routing is a way of connecting devices without setting an IP on the interface that is being routed to/from. The other end uses the routing protocol on top of layer 2, and while the two might have a router ID, often in the form of an IP address, the interface that is connecting the two has no IP. It’s basically advanced point to point protocol (PPP) that breaks away from traditional TCP/IP routing in ways that people who have never used anything besides TCP/IP can’t really comprehend. The two “IP addresses” (actually router IDs) in play can have nothing in common. Traditional TCP/IP requires that two IPs share a subnet. In routing, this is typically a /30 for IPv4, and the two IPs are adjacent to eachother, eg, 10.254.123.1 and 10.254.123.2
IP unnumbered can have 10.254.123.2 talking directly with 172.30.88.207, with no layer 3 interfaces in-between.
It’s really fascinating and interesting and I’ve been trying to find a good model or guide to help me learn this better, but I keep ending up at dead ends, and I have nobody to talk to about it.
Sounds like you should look at IS-IS protocol if you haven’t as that’s very close to the ip unnumbered routing you were talking about. Though isis is usually deployed with its on the interface of each device, it doesn’t have to be AFAIK.
I’m not sure that I understand the benefit of “unnumbered” routing. It sounds like there are numbers (well, “identifiers”), just not IP addresses.
It’s hard to know without more context, but you can use things like IPv6 multicast to manage reachability. This will let you set arbitrary sets of endpoints that talk to each other, and you can still us IP-based tools to debug connectivity, measure performance, and so on.
The benefits are pretty simple but have broader implications than what would be apparent on the surface.
Let me lay down a little ground work first. Traditionally with routing protocols you need to implement a /30 between interfaces on the connected devices before routing will come up. Usually that requires the use of IPAM, and a lot of record keeping to ensure nothing overlaps.
So let’s take the example of a relatively simple spine and leaf topology. A leaf switch dies, or otherwise needs replacing. You set up the new leaf with a template, which contains pretty much all the routing commands you’ll need, and all of your overlay transport, VLAN definitions, and whatever. After that, you need to program the uplink interfaces to the spine(s) - hopefully at least two - in order to get it online.
If you’re doing a replacement because a switch died, looking up the interface IP assignments for the leaf is going to take a lot of time, nevermind programming the addresses, and all the possible fat finger typos that could happen, just to get the switch communicating in your underlay (and to your management systems).
In small networks, not a big deal, you’re dealing with maybe a dozen such devices at most, but in large scale provider, datacenter, or hyperscale networks with literally hundreds of racks, each with a top-of-rack leaf switch, good luck.
Enter IP unnumbered. Same situation. You can pre-prepare any standby switches with unique loopback IPs in the routing system, and mark them as used in the IPAM for a standby device. A failure happens, you grab a standby switch and head to the rack. Next you yank all of the port connections out and plug them into the standby switch and power it up ASAP. Without touching the config at all, it grabs the routing and comes online, and the NOC can simply apply the port config for that rack on that switch from their management console.
This can easily cut repair time in half or better.
Any switch can be moved anywhere in the enjoyment and it will come online right away.
So this isn’t about routing really, rather about optimizing standby routers for recovery.
A few things make me nervous.
First, the description of the work involved seems to imply that your setup really needs more automated tooling. Nontrivial, but you’ve already mentioned typos, and that this is for large operations.
Second, using IPv4 for your management network is wasteful and needlessly complicated. Even if your customer traffic is all IPv4, there’s really no reason to use legacy protocols for internal routing.
Now-a-days, I want to have conversations about the merits of one routing protocol over another in various contexts, and see/build a spine and leaf network infrastructure that’s nearly infinitely scalable.
bro i just want screensharing that isn’t using the hell that is webrtc.
How hard is it to send video packets over IP, it can’t be that difficult. Half the job is already done, and i can’t imagine building a reliable networking protocol, even if you had to do it from scratch would be particularly hard.
See, I only recently came into awareness that web RTC was a thing. I have a lot of learning to do on how it even works as a protocol.
I’m sure it runs on top of IP, so I think web RTC meets your curriculum here. Regardless of that, I think I know what you mean, and if I knew enough about the protocol, I might even agree.
I need to brush up on the new protocols that are getting to be very common. I’m almost entirely up to date on the 802.11 specs, but there’s so much to keep track of… Yikes.
Did my fair share of networking back in the day, but never heard of IP unnumbered. I was curious about the same idea back in the day and it is possible, but I haven’t much seen anyone doing it for realsies. If you have any good longreads/vids on the topic, it’d be much appreciated.
What’s your day job? From my understanding if you can get a CCNP you’re gonna be making over 100k after a few years if you’re able to get your foot in the door experience wise
There’s the problem. I can’t get my foot in the door for network-centered jobs. I have a ton of experience, and a CCNA, but all my experience is while working as a generalist in an MSP.
There’s a sort of curse in the industry where map work is easy to get into from college/uni, but hard to evolve away from.
Bringing a website online sounds a lot more like development stuff.
Networking is all about how to get data from one place to another that is reasonable, manageable and scalable. Knowing what devices are increasing latency and when you should adjust the settings to route around a high latency (and/or high loss) link to enhance performance and reliability. Visibility into network flows in real time and monitoring for every link and port that’s connected to a device, switch, router, or computer.
Web hosting is system admin and development.
What networking concerns do you have with this website?
Not a scientist. I have a litany of complex topics that I just can’t really talk to anyone about. I’m a big computer networking nerd, and once upon a time, when I didn’t know what I didn’t know, I was curious what computer networking really entailed… It seemed dead simple, you connect things to a switch, connect that switch to the internet router, not much more.
Then I learned about VLANs, which are cool but it seemed like unnecessary complexity. Then I learned about Routing and L3 switching, and routing protocols and… Holy shit, how deep is this?
Now-a-days, I want to have conversations about the merits of one routing protocol over another in various contexts, and see/build a spine and leaf network infrastructure that’s nearly infinitely scalable.
I want to explore the nuance of IP unnumbered routing. I can’t find anyone who will chat about it on a level that’s close to my understanding, either someone knows way more than I do, or they know way less.
IP unnumbered routing is a way of connecting devices without setting an IP on the interface that is being routed to/from. The other end uses the routing protocol on top of layer 2, and while the two might have a router ID, often in the form of an IP address, the interface that is connecting the two has no IP. It’s basically advanced point to point protocol (PPP) that breaks away from traditional TCP/IP routing in ways that people who have never used anything besides TCP/IP can’t really comprehend. The two “IP addresses” (actually router IDs) in play can have nothing in common. Traditional TCP/IP requires that two IPs share a subnet. In routing, this is typically a /30 for IPv4, and the two IPs are adjacent to eachother, eg, 10.254.123.1 and 10.254.123.2 IP unnumbered can have 10.254.123.2 talking directly with 172.30.88.207, with no layer 3 interfaces in-between.
It’s really fascinating and interesting and I’ve been trying to find a good model or guide to help me learn this better, but I keep ending up at dead ends, and I have nobody to talk to about it.
Sounds like you should look at IS-IS protocol if you haven’t as that’s very close to the ip unnumbered routing you were talking about. Though isis is usually deployed with its on the interface of each device, it doesn’t have to be AFAIK.
I’m not sure that I understand the benefit of “unnumbered” routing. It sounds like there are numbers (well, “identifiers”), just not IP addresses.
It’s hard to know without more context, but you can use things like IPv6 multicast to manage reachability. This will let you set arbitrary sets of endpoints that talk to each other, and you can still us IP-based tools to debug connectivity, measure performance, and so on.
The benefits are pretty simple but have broader implications than what would be apparent on the surface.
Let me lay down a little ground work first. Traditionally with routing protocols you need to implement a /30 between interfaces on the connected devices before routing will come up. Usually that requires the use of IPAM, and a lot of record keeping to ensure nothing overlaps.
So let’s take the example of a relatively simple spine and leaf topology. A leaf switch dies, or otherwise needs replacing. You set up the new leaf with a template, which contains pretty much all the routing commands you’ll need, and all of your overlay transport, VLAN definitions, and whatever. After that, you need to program the uplink interfaces to the spine(s) - hopefully at least two - in order to get it online.
If you’re doing a replacement because a switch died, looking up the interface IP assignments for the leaf is going to take a lot of time, nevermind programming the addresses, and all the possible fat finger typos that could happen, just to get the switch communicating in your underlay (and to your management systems).
In small networks, not a big deal, you’re dealing with maybe a dozen such devices at most, but in large scale provider, datacenter, or hyperscale networks with literally hundreds of racks, each with a top-of-rack leaf switch, good luck.
Enter IP unnumbered. Same situation. You can pre-prepare any standby switches with unique loopback IPs in the routing system, and mark them as used in the IPAM for a standby device. A failure happens, you grab a standby switch and head to the rack. Next you yank all of the port connections out and plug them into the standby switch and power it up ASAP. Without touching the config at all, it grabs the routing and comes online, and the NOC can simply apply the port config for that rack on that switch from their management console.
This can easily cut repair time in half or better.
Any switch can be moved anywhere in the enjoyment and it will come online right away.
So this isn’t about routing really, rather about optimizing standby routers for recovery.
A few things make me nervous.
First, the description of the work involved seems to imply that your setup really needs more automated tooling. Nontrivial, but you’ve already mentioned typos, and that this is for large operations.
Second, using IPv4 for your management network is wasteful and needlessly complicated. Even if your customer traffic is all IPv4, there’s really no reason to use legacy protocols for internal routing.
bro i just want screensharing that isn’t using the hell that is webrtc.
How hard is it to send video packets over IP, it can’t be that difficult. Half the job is already done, and i can’t imagine building a reliable networking protocol, even if you had to do it from scratch would be particularly hard.
everything is webrtc, it always has been.
See, I only recently came into awareness that web RTC was a thing. I have a lot of learning to do on how it even works as a protocol.
I’m sure it runs on top of IP, so I think web RTC meets your curriculum here. Regardless of that, I think I know what you mean, and if I knew enough about the protocol, I might even agree.
I need to brush up on the new protocols that are getting to be very common. I’m almost entirely up to date on the 802.11 specs, but there’s so much to keep track of… Yikes.
Did my fair share of networking back in the day, but never heard of IP unnumbered. I was curious about the same idea back in the day and it is possible, but I haven’t much seen anyone doing it for realsies. If you have any good longreads/vids on the topic, it’d be much appreciated.
Should shoot me a DM, have been studying for my CCNP and do want more networking buddies to potentially socialize with.
I’ve been looking at the CCNP for a while, I don’t need it for the work I do at my day job, so I haven’t prioritized taking the test or anything.
I should do more work on it.
What’s your day job? From my understanding if you can get a CCNP you’re gonna be making over 100k after a few years if you’re able to get your foot in the door experience wise
There’s the problem. I can’t get my foot in the door for network-centered jobs. I have a ton of experience, and a CCNA, but all my experience is while working as a generalist in an MSP.
There’s a sort of curse in the industry where map work is easy to get into from college/uni, but hard to evolve away from.
I need some help with networking and eventually getting an organisation website online; if you want to geek out a bit, please send me a dm. :)
Bringing a website online sounds a lot more like development stuff.
Networking is all about how to get data from one place to another that is reasonable, manageable and scalable. Knowing what devices are increasing latency and when you should adjust the settings to route around a high latency (and/or high loss) link to enhance performance and reliability. Visibility into network flows in real time and monitoring for every link and port that’s connected to a device, switch, router, or computer.
Web hosting is system admin and development.
What networking concerns do you have with this website?