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87 votes
Accepted

Is "IPv10" a joke or a serious RFC draft?

As Ron said, anyone can write a proposal. I have a hard time taking proposals seriously from someone who suggests interconnecting satellites with optical fiber, though. Also, I can't imagine this ...
Teun Vink's user avatar
  • 17.4k
28 votes

Is "IPv10" a joke or a serious RFC draft?

You must remember that anyone can submit proposals to the IETF, and they are taken seriously, until they are either adopted or die due to lack of interest. This particular proposal has expired and ...
Ron Maupin's user avatar
  • 99.8k
28 votes

What is the practical use of a /31 CIDR or 255.255.255.254?

A /31 network actually has two usable hosts for a point-to-point link. See the Standards Track RFC 3021, Using 31-Bit Prefixes on IPv4 Point-to-Point Links (published in December 2000): Abstract With ...
Ron Maupin's user avatar
  • 99.8k
25 votes
Accepted

acknowledgment by TCP does not guarantee that the data has been delivered

This part of the RFC is about passing responsibility over to the operating system or whatever is the next stage of the process. It's fundamentally concerned with the separation of layers. An ...
jonathanjo's user avatar
  • 16.3k
20 votes

Where can I use the IPv6 documentation prefix

The IPv6 documentation prefix (2001:db8:::/32) must be used ONLY for documentation purposes. It means written examples, diagrams, PPT presentations, Textbook explanations, etc. This range shouldn't ...
jcbermu's user avatar
  • 4,497
19 votes
Accepted

IPv4 Segment 100.64.0.0/10

The 100.64.0.0/10 address block is not private address space; it is shared address space. This is spelled out in RFC 6598, IANA-Reserved IPv4 Prefix for Shared Address Space (I highlighted the ...
Ron Maupin's user avatar
  • 99.8k
19 votes
Accepted

Why are there 3 ranges of private IPv4 addresses?

Back when the RFC for private addressing was proposed, classful addressing was still common. The reasons for the three address ranges are found in RFC 1918, Address Allocation for Private Internets: ...
Ron Maupin's user avatar
  • 99.8k
19 votes

Is "IPv10" a joke or a serious RFC draft?

Is “IPv10” a joke or a serious RFC draft? Both. That draft doesn't solve a single problem but opens a can of new ones. I guess that bloke is serious and he doesn't get what ridiculous schemes he's ...
Zac67's user avatar
  • 84.9k
16 votes

Usage of Flow label in IPv6 header?

The above answer isn't really correct. The flow label isn't designed for packet ordering - IP does not care about order, it is an unreliable services whose only goal is delivery on layer3. Better way ...
J M-A's user avatar
  • 161
11 votes
Accepted

Where can I use the IPv6 documentation prefix

If your test environment is separated from your local network you hypothetically could use any IPv6 addresses which are not reserved for special uses. However, if you are looking for an equivalent of ...
mushr00mer1990's user avatar
10 votes
Accepted

Should a router use SLAAC for IPv6 address assignment?

In RFC 7084, it also states: W-1: When the router is attached to the WAN interface link, it MUST act as an IPv6 host for the purposes of stateless [RFC4862] or stateful [RFC3315] interface address ...
Benjamin Dale's user avatar
10 votes

acknowledgment by TCP does not guarantee that the data has been delivered

From the RFC perspective, the "end user" is the application. There's no guarantee that the application got the data, just that the TCP process received it. From your NOC perspective, the network is ...
Ron Trunk's user avatar
  • 67.6k
10 votes
Accepted

Where are 0 TCP/UDP ports banned?

IANA has reserved both TCP and UDP port 0. See the IANA Service Name and Transport Protocol Port Number Registry. IANA is the Internet Assigned Numbers Authority, so all internet numbers, including ...
Ron Maupin's user avatar
  • 99.8k
9 votes
Accepted

Why isn't 10.0.0.0/8 used instead of 192.168.0.0/16 for private addresses?

It is merely a necessity constraint and personal preference. If a Network is being built that would only have 10, or 20, or 50, or even 100 hosts, there is no reason not to use a /24 from 192.168.0....
Eddie's user avatar
  • 15k
9 votes

Where are 0 TCP/UDP ports banned?

TL;DR: RFC870 Port zero has been included in the "Network Wide Standard Functions" range since RFC433 in 1972, but has never been assigned. https://www.rfc-editor.org/rfc/rfc433.html Here ...
Ben's user avatar
  • 191
8 votes

IPv4 Segment 100.64.0.0/10

That block of addresses is reserved for service providers to be able to do NAT in such a way that it doesn't conflict with the normal private address space. If you start using it as private space then ...
Sander Steffann's user avatar
8 votes

IPv4 Segment 100.64.0.0/10

Officially RFC 6598 says Devices MUST be capable of performing address translation when identical Shared Address Space ranges are used on two different interfaces. Most NAT ...
Peter Green's user avatar
  • 13.3k
8 votes

Where can I use the IPv6 documentation prefix

Just from the RFC I can't see anything defining that documentation is strictly written text. Do you have any source for this interpretation? According to the IANA IPv6 Special-Purpose Address ...
Ron Maupin's user avatar
  • 99.8k
8 votes
Accepted

What MAC address do I use to generate a IPv6 Pseudo-Random Global ID

Remember, the purpose of the algorithm is to avoid everyone picking FD00::/48 so they can abbreviate everything with the double colon. (Or other "easy" ones like FDAA:AAAA::/48, etc). The ...
Eddie's user avatar
  • 15k
8 votes
Accepted

Class A most significant bits '0' as in RFC1166 or older or '00' as suggested in RFC4632?

It appears to be a typo in that RFC. Notice that the header of the RFC says Errata Exist. It is not uncommon for things like that to happen. That particular error is corrected in the errata. See the ...
Ron Maupin's user avatar
  • 99.8k
7 votes

Should a router use SLAAC for IPv6 address assignment?

RFC 4862 really describes routers within a single administrative control. RFC 7084 clarifies how customer routers should behave. This gives an ISP some freedom in how it supports IPv6 to its customers....
Ron Maupin's user avatar
  • 99.8k
7 votes

Is Per Vlan Spanning Tree or RPVST an open standard or can it only be implemented by Cisco?

(R)PVST(+) is a proprietary standard defined by Cisco (or a set thereof). However, there are many other vendors and devices supporting it - you may need to check the specifications of your devices. ...
Zac67's user avatar
  • 84.9k
6 votes

Should a router use SLAAC for IPv6 address assignment?

Why does RFC 4862 say "Since host autoconfiguration uses information advertised by routers, routers will need to be configured by some other means." The people who wrote that document (and it's ...
Peter Green's user avatar
  • 13.3k
5 votes

How do the Telnet requests "DO" and "WILL" differ?

What is the difference between the WILL and DO request? There is a very important concept involved here, that you need to understand when implementing a Telnet server or client, otherwise your ...
blubberdiblub's user avatar
5 votes

Why are there 3 ranges of private IPv4 addresses?

While not an great answer (Ron Maupin's is more accurate), I was always taught to always use the the smallest class that left 10% room for expansion. This was "very important" with a facility that had ...
coteyr's user avatar
  • 151
5 votes
Accepted

How do ICMP packets travel in a networks?

It is indeed specified in RFC 792, on the top of page 2: Message Formats ICMP messages are sent using the basic IP header. You will also found in this RFC : ICMP, uses the basic support of IP as ...
JFL's user avatar
  • 19.7k
5 votes
Accepted

Suggestion for Weights for Weighted Round Robin

14 egress queues seems a bit excessive - most devices I dealt with use 3, 4 (most common), or up to 8 queues. I'd just use four which simplifies things: critical traffic (very low-bandwidth, critical ...
Zac67's user avatar
  • 84.9k
5 votes
Accepted

Why do we need private IP address range?

RFC 1918 provides address ranges that you can safely use within a private network without any danger that these same addresses might be used on the public Internet. Any node within your network needs ...
Zac67's user avatar
  • 84.9k
4 votes

Usage of Flow label in IPv6 header?

Semantics and Usage of the Flow Label Field A flow is a sequence of packets sent from a particular source to a  particular (unicast or multicast) destination for which the source  desires special ...
The Room's user avatar
  • 141
4 votes

IP packet reading

The unit used in the Length field is not bit nor even byte but 32bits words. So the value 5 correspond to five 32 bits words = 160 bits = 20 bytes. And the max value is then 15 x 32 bits = 60 bytes (...
JFL's user avatar
  • 19.7k

Only top scored, non community-wiki answers of a minimum length are eligible