Timeline for Problem with longest prefix matching
Current License: CC BY-SA 4.0
13 events
| when toggle format | what | by | license | comment | |
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| Jan 7, 2021 at 0:54 | comment | added | Ron Maupin♦ | Did any answer help you? If so, you should accept the answer so that the question doesn't keep popping up forever, looking for an answer. Alternatively, you can post and accept your own answer. | |
| Jun 6, 2018 at 23:58 | answer | added | Ricky | timeline score: 0 | |
| Jun 6, 2018 at 8:34 | answer | added | Tomasz Pala | timeline score: 0 | |
| Jun 5, 2018 at 17:22 | comment | added | Ron Maupin♦ | Aside from the anycast concept, you cannot have duplicate addressing because that introduces ambiguity, and routing is deterministic. You can have multiple, duplicate networks, but the duplicate networks must be hidden behind NAT, so that there doesn't appear to be duplicate networks. That is how private addressing is used. To the public, you have unique public addressing, but behind the NAT you may have a network used behind a different NAT. This breaks the IP end-to-end paradigm, and it causes other problems. In any case, a public router never sees the duplicate networks. | |
| Jun 5, 2018 at 17:17 | comment | added | Vishal Rana | @RonMaupin thanks for such a nice answer. So are you trying to say that we can have only network 192.24.12.0/22 as a subnet of 192.24.0.0/18 and not as any separate network on the Internet? I think I have not understood something due to which this inconsistency is arising. | |
| Jun 5, 2018 at 15:25 | comment | added | Ron Maupin♦ | Routers route between networks, and routing must be deterministic. A router cannot have interfaces with overlapping networks because the router could use the wrong interface for traffic. Remember that IP packets only have IP addresses, not masks, for the the destination. | |
| Jun 5, 2018 at 15:22 | comment | added | Ron Maupin♦ |
No. That would imply you could have two hosts with the same address. For example, two hosts addressed as 192.24.12.33, one on each network. Addressing must be unique unless you have some kludge like NAT, but then one router would not have both networks.
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| Jun 5, 2018 at 15:13 | comment | added | Vishal Rana | @RonMaupin Can't we have two such networks located separately? | |
| Jun 5, 2018 at 14:55 | comment | added | Ron Maupin♦ |
The problem is that 192.24.12.0/22 is part of 192.24.0.0/18, and not a separate network at all.
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| Jun 5, 2018 at 11:42 | answer | added | Zac67♦ | timeline score: 5 | |
| Jun 5, 2018 at 11:23 | comment | added | Ron Trunk | The first part of your question is correct, but the second part of your question isn't clear what you're asking. If a packet matches two entries in the routing table, the longest match wins. | |
| Jun 5, 2018 at 10:57 | review | First posts | |||
| Jun 5, 2018 at 14:23 | |||||
| Jun 5, 2018 at 10:56 | history | asked | Vishal Rana | CC BY-SA 4.0 |