4 Protocol Examples

Article
06/24/2021

The following example illustrates an LLMNR query for AAAA resource records for a host name that starts with a non-ASCII character (represented in UTF-8 encoding) and the corresponding response, which contains multiple AAAA resource records that make the response larger than the 512-octet UDP payload limit observed by DNS:

UDP/IPv6 packet containing the AAAA LLMNR query for host name "çest":

  
 - Ipv6:
     Versions: IPv6, Internet Protocol, DSCP 0
     PayloadLength: 31 (0x1F)
     NextProtocol: 17(0x11)
     HopLimit: 1 (0x1)
     SourceAddress: FE80:0:0:0:D9F6:CE2E:4875:AB03
     DestinationAddress: FF02:0:0:0:0:0:1:3
 - Udp:
     SourcePort: 62925(0xf5cd)
     DestinationPort: 5355(0x14eb)
     TotalLength: 31 (0x1F)
     Checksum: 37373 (0x91FD)
 - Llmnr:
     QueryIdentifier: 35893 (0x8C35)
   - Flags:
      QR:       (0...............) Query
      OPCode:   (.0000...........) Standard
      C:        (.....0..........) 
      TC:       (......0.........) 
      T:        (.......0........) 
      Reserved: (........0000....)
      RCode:    (............0000) Success
     QuestionCount: 1 (0x1)
     AnswerCount: 0 (0x0)
     NameServerCount: 0 (0x0)
     AdditionalCount: 0 (0x0)
   - QRecord:
      QuestionName: çest (0x05 0xC3 0xA7 0x65 0x73 0x74 0x00)
      QuestionType: AAAA, 28(0x1c)
      QuestionClass: Internet, 1(0x1)

UDP/IPv6 packet containing the LLMNR response, which includes 25 AAAA resource records. In the following example, all 25 IP addresses belong to interfaces on the same host and are thus not in conflict.

  
 - Ipv6:
   - Versions: IPv6, Internet Protocol, DSCP 0
     PayloadLength: 736 (0x2E0)
     NextProtocol: 17(0x11)
     HopLimit: 64 (0x40)
     SourceAddress: FE80:0:0:0:0:0:0:100
     DestinationAddress: FE80:0:0:0:D9F6:CE2E:4875:AB03
 - Udp:
     SourcePort: 5355(0x14eb)
     DestinationPort: 62925(0xf5cd)
     TotalLength: 736 (0x2E0)
     Checksum: 9332 (0x2474)
 - Llmnr:
     QueryIdentifier: 35893 (0x8C35)
   - Flags:
      QR:       (1...............) Response
      OPCode:   (.0000...........) Standard
      C:        (.....0..........) 
      TC:       (......0.........) 
      T:        (.......0........) 
      Reserved: (........0000....)
      RCode:    (............0000) Success
     QuestionCount: 1 (0x1)
     AnswerCount: 25 (0x19)
     NameServerCount: 0 (0x0)
     AdditionalCount: 0 (0x0)
   - QRecord:
      QuestionName: çest (0x05 0xC3 0xA7 0x65 0x73 0x74 0x00)
      QuestionType: AAAA, 28(0x1c)
      QuestionClass: Internet, 1(0x1)
   - ARecord:
      ResourceName: çest (0x05 0xC3 0xA7 0x65 0x73 0x74 0x00)
      ResourceType: AAAA, 28(0x1c)
      ResourceClass: Internet, 1(0x1)
      TimeToLive: 30 (0x1E)
      ResourceDataLength: 16 (0x10)
      IPv6Address: 2001:4898:1B:5:709F:3CF3:698E:AB15
   - ARecord:
      ResourceName: çest (0xC0 0x17)
      ResourceType: AAAA, 28(0x1c)
      ResourceClass: Internet, 1(0x1)
      TimeToLive: 30 (0x1E)
      ResourceDataLength: 16 (0x10)
      IPv6Address: 2002:9D3B:1DF3:8:709F:3CF3:698E:AB15
   - ARecord: 
      ResourceName: çest (0xC0 0x17)
      ResourceType: AAAA, 28(0x1c)
      ResourceClass: Internet, 1(0x1)
      TimeToLive: 30 (0x1E)
      ResourceDataLength: 16 (0x10)
      IPv6Address: FEC0:0:0:8:709F:3CF3:698E:AB15
   - ARecord: 
      ResourceName: çest (0xC0 0x17)
      ResourceType: AAAA, 28(0x1c)
      ResourceClass: Internet, 1(0x1)
      TimeToLive: 30 (0x1E)
      ResourceDataLength: 16 (0x10)
      IPv6Address: FE80:0:0:0:0:0:0:100
   - ARecord: 
      ResourceName: çest (0xC0 0x17)
      ResourceType: AAAA, 28(0x1c)
      ResourceClass: Internet, 1(0x1)
      TimeToLive: 30 (0x1E)
      ResourceDataLength: 16 (0x10)
      IPv6Address: FE80:0:0:0:0:0:0:101
   - ARecord: 
      ResourceName: çest (0xC0 0x17)
      ResourceType: AAAA, 28(0x1c)
      ResourceClass: Internet, 1(0x1)
      TimeToLive: 30 (0x1E)
      ResourceDataLength: 16 (0x10)
      IPv6Address: FE80:0:0:0:0:0:0:102
   - ARecord: 
      ResourceName: çest (0xC0 0x17)
      ResourceType: AAAA, 28(0x1c)
      ResourceClass: Internet, 1(0x1)
      TimeToLive: 30 (0x1E)
      ResourceDataLength: 16 (0x10)
      IPv6Address: FE80:0:0:0:0:0:0:103
   - ARecord: 
      ResourceName: çest (0xC0 0x17)
      ResourceType: AAAA, 28(0x1c)
      ResourceClass: Internet, 1(0x1)
      TimeToLive: 30 (0x1E)
      ResourceDataLength: 16 (0x10)
      IPv6Address: FE80:0:0:0:0:0:0:104
   - ARecord: 
      ResourceName: çest (0xC0 0x17)
      ResourceType: AAAA, 28(0x1c)
      ResourceClass: Internet, 1(0x1)
      TimeToLive: 30 (0x1E)
      ResourceDataLength: 16 (0x10)
      IPv6Address: FE80:0:0:0:0:0:0:105
   - ARecord: 
      ResourceName: çest (0xC0 0x17)
      ResourceType: AAAA, 28(0x1c)
      ResourceClass: Internet, 1(0x1)
      TimeToLive: 30 (0x1E)
      ResourceDataLength: 16 (0x10)
      IPv6Address: FE80:0:0:0:0:0:0:106
   - ARecord: 
      ResourceName: çest (0xC0 0x17)
      ResourceType: AAAA, 28(0x1c)
      ResourceClass: Internet, 1(0x1)
      TimeToLive: 30 (0x1E)
      ResourceDataLength: 16 (0x10)
      IPv6Address: FE80:0:0:0:0:0:0:107
   - ARecord: 
      ResourceName: çest (0xC0 0x17)
      ResourceType: AAAA, 28(0x1c)
      ResourceClass: Internet, 1(0x1)
      TimeToLive: 30 (0x1E)
      ResourceDataLength: 16 (0x10)
      IPv6Address: FE80:0:0:0:0:0:0:108
   - ARecord: 
      ResourceName: çest (0xC0 0x17)
      ResourceType: AAAA, 28(0x1c)
      ResourceClass: Internet, 1(0x1)
      TimeToLive: 30 (0x1E)
      ResourceDataLength: 16 (0x10)
      IPv6Address: FE80:0:0:0:0:0:0:109
   - ARecord: 
      ResourceName: çest (0xC0 0x17)
      ResourceType: AAAA, 28(0x1c)
      ResourceClass: Internet, 1(0x1)
      TimeToLive: 30 (0x1E)
      ResourceDataLength: 16 (0x10)
      IPv6Address: FE80:0:0:0:0:0:0:110
   - ARecord: 
      ResourceName: çest (0xC0 0x17)
      ResourceType: AAAA, 28(0x1c)
      ResourceClass: Internet, 1(0x1)
      TimeToLive: 30 (0x1E)
      ResourceDataLength: 16 (0x10)
      IPv6Address: FE80:0:0:0:0:0:0:111
   - ARecord: 
      ResourceName: çest (0xC0 0x17)
      ResourceType: AAAA, 28(0x1c)
      ResourceClass: Internet, 1(0x1)
      TimeToLive: 30 (0x1E)
      ResourceDataLength: 16 (0x10)
      IPv6Address: FE80:0:0:0:0:0:0:112
   - ARecord: 
      ResourceName: çest (0xC0 0x17)
      ResourceType: AAAA, 28(0x1c)
      ResourceClass: Internet, 1(0x1)
      TimeToLive: 30 (0x1E)
      ResourceDataLength: 16 (0x10)
      IPv6Address: FE80:0:0:0:0:0:0:113
   - ARecord: 
      ResourceName: çest (0xC0 0x17)
      ResourceType: AAAA, 28(0x1c)
      ResourceClass: Internet, 1(0x1)
      TimeToLive: 30 (0x1E)
      ResourceDataLength: 16 (0x10)
      IPv6Address: FE80:0:0:0:0:0:0:114
   - ARecord: 
      ResourceName: çest (0xC0 0x17)
      ResourceType: AAAA, 28(0x1c)
      ResourceClass: Internet, 1(0x1)
      TimeToLive: 30 (0x1E)
      ResourceDataLength: 16 (0x10)
      IPv6Address: FE80:0:0:0:0:0:0:115
   - ARecord: 
      ResourceName: çest (0xC0 0x17)
      ResourceType: AAAA, 28(0x1c)
      ResourceClass: Internet, 1(0x1)
      TimeToLive: 30 (0x1E)
      ResourceDataLength: 16 (0x10)
      IPv6Address: FE80:0:0:0:0:0:0:116
   - ARecord: 
      ResourceName: çest (0xC0 0x17)
      ResourceType: AAAA, 28(0x1c)
      ResourceClass: Internet, 1(0x1)
      TimeToLive: 30 (0x1E)
      ResourceDataLength: 16 (0x10)
      IPv6Address: FE80:0:0:0:0:0:0:117
   - ARecord: 
      ResourceName: çest (0xC0 0x17)
      ResourceType: AAAA, 28(0x1c)
      ResourceClass: Internet, 1(0x1)
      TimeToLive: 30 (0x1E)
      ResourceDataLength: 16 (0x10)
      IPv6Address: FE80:0:0:0:0:0:0:118
   - ARecord: 
      ResourceName: çest (0xC0 0x17)
      ResourceType: AAAA, 28(0x1c)
      ResourceClass: Internet, 1(0x1)
      TimeToLive: 30 (0x1E)
      ResourceDataLength: 16 (0x10)
      IPv6Address: FE80:0:0:0:0:0:0:119
   - ARecord: 
      ResourceName: çest (0xC0 0x17)
      ResourceType: AAAA, 28(0x1c)
      ResourceClass: Internet, 1(0x1)
      TimeToLive: 30 (0x1E)
      ResourceDataLength: 16 (0x10)
      IPv6Address: FE80:0:0:0:0:0:0:120
   - ARecord: 
      ResourceName: çest (0xC0 0x17)
      ResourceType: AAAA, 28(0x1c)
      ResourceClass: Internet, 1(0x1)
      TimeToLive: 30 (0x1E)
      ResourceDataLength: 16 (0x10)
      IPv6Address: FE80:0:0:0:709F:3CF3:698E:AB15

4 Protocol Examples

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