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398c2e1921
@ -159,7 +159,7 @@ this:
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Note that we did not spend time on field Z, this is because it is defined to
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Note that we did not spend time on field Z, this is because it is defined to
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be 0 at all times. This packets does not request recursion. QDCOUNT = 1
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be 0 at all times. This packet does not request recursion. QDCOUNT = 1
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means there is 1 question. In theory DNS supported several questions in one
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means there is 1 question. In theory DNS supported several questions in one
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message, but this has not been implemented. ANCOUNT, NSCOUNT and ARCOUNT
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message, but this has not been implemented. ANCOUNT, NSCOUNT and ARCOUNT
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are all zero, indicating there as no answers in this question packet.
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are all zero, indicating there as no answers in this question packet.
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@ -190,7 +190,7 @@ Here is the actual question:
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* +--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+ *
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* +--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+ *
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********************************************************
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********************************************************
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This consists of the 'www.ietf.org' encoded in DNS wire format (for which
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This consists of the name 'www.ietf.org' encoded in DNS wire format (for which
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see below), followed by a 16 bit type field. For AAAA, which denotes the
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see below), followed by a 16 bit type field. For AAAA, which denotes the
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IPv6 address, this is 28. This is then followed by the 'class' of the
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IPv6 address, this is 28. This is then followed by the 'class' of the
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question. It was originally intended that DNS records would exist in
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question. It was originally intended that DNS records would exist in
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@ -206,7 +206,7 @@ trailing 0 which denotes this is the end.
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This format is unusual, but has several highly attractive properties. For
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This format is unusual, but has several highly attractive properties. For
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example, it is binary safe and it needs no escaping. When writing DNS
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example, it is binary safe and it needs no escaping. When writing DNS
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software, it may be tempting to pass DNS names around as "ASCII". This then
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software, it may be tempting to pass DNS names around as "ASCII". This then
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leads to escaping an unescaping code in lots of places. It is highly
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leads to escaping and unescaping code in lots of places. It is highly
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recommended to use the native DNS encoding to store DNS names. This will
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recommended to use the native DNS encoding to store DNS names. This will
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save a lot of pain when processing DNS names with spaces or dots in them.
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save a lot of pain when processing DNS names with spaces or dots in them.
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@ -532,7 +532,7 @@ response with AA=0, indicating that the 'org' servers know they aren't
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### Glue records
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### Glue records
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The astute reader will have spotted a chicken and egg problem here. If
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The astute reader will have spotted a chicken and egg problem here. If
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ns1.ietf.org is the nameserver for ietf.org.. where do we get the IP
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ns1.ietf.org is the nameserver for ietf.org., where do we get the IP
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address of ns1.ietf.org?
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address of ns1.ietf.org?
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To solve this problem, the parent zone can provide a free chicken. In the
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To solve this problem, the parent zone can provide a free chicken. In the
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