IPv6 Overview
507
■
The selected route is not the default route.
■
The forwarded IPv6 packet does not contain any routing header.
IPv6 PMTU Discovery
The links that a packet passes from the source to the destination may have
different MTUs. In IPv6, when the packet size exceeds the link MTU, the packet
will be fragmented at the source end so as to reduce the processing pressure of
the forwarding device and utilize network resources rationally.
The path MTU (PMTU) discovery mechanism is to find the minimum MTU of all
links in the path from the source to the destination. Figure 154 shows the working
procedure of the PMTU discovery.
Figure 154
Working procedure of the PMTU discovery
The working procedure of the PMTU discovery is as follows:
1
The source host uses its MTU to fragment packets and then sends them to the
destination host.
2
If the MTU supported by the forwarding interface is less than the packet size, the
forwarding device will discard the packet and return an ICMPv6 error packet
containing the interface MTU to the source host.
3
After receiving the ICMPv6 error packet, the source host uses the returned MTU to
fragment the packet again and then sends it.
4
Step 2 to step 3 are repeated until the destination host receives the packet. In this
way, the minimum MTU of all links in the path from the source host to the
destination host is determined.
Introduction to IPv6 DNS
In the IPv6 network, a Domain Name System (DNS) supporting IPv6 converts
domain names into IPv6 addresses, instead of IPv4 addresses.
However, just like an IPv4 DNS, an IPv6 DNS also covers static domain name
resolution and dynamic domain name resolution. The function and
implementation of these two types of domain name resolution are the same as
those of an IPv4 DNS. For details, refer to “DNS Overview” on page 971.
Usually, the DNS server connecting IPv4 and IPv6 networks not only contain A
records (IPv4 addresses), but also AAAA records (IPv6 addresses). The DNS server
can convert domain names into IPv4 addresses or IPv6 addresses. In this way, the
DNS server implements the functions of both IPv6 DNS and IPv4 DNS.
Source
MTU = 1500
MTU = 1500
MTU = 1350
MTU = 1400
Packet with MTU = 1500
ICMP error: packet too big;
use MTU = 1350
Packet with MTU = 1350
Packet received
Содержание 4800G Series
Страница 26: ...26 CHAPTER NETWORKING APPLICATIONS ...
Страница 30: ...30 CHAPTER 1 LOGGING IN TO AN ETHERNET SWITCH ...
Страница 62: ...62 CHAPTER 3 LOGGING IN THROUGH TELNET ...
Страница 70: ...70 CHAPTER 5 LOGGING IN THROUGH WEB BASED NETWORK MANAGEMENT SYSTEM ...
Страница 72: ...72 CHAPTER 6 LOGGING IN THROUGH NMS ...
Страница 82: ...82 CHAPTER 8 CONTROLLING LOGIN USERS ...
Страница 98: ...98 CHAPTER 9 VLAN CONFIGURATION ...
Страница 108: ...108 CHAPTER 10 VOICE VLAN CONFIGURATION ...
Страница 119: ...GVRP Configuration Examples 119 DeviceB display vlan dynamic No dynamic vlans exist ...
Страница 120: ...120 CHAPTER 11 GVRP CONFIGURATION ...
Страница 160: ...160 CHAPTER 17 PORT ISOLATION CONFIGURATION ...
Страница 172: ...172 CHAPTER 19 LINK AGGREGATION CONFIGURATION ...
Страница 196: ...196 CHAPTER 22 DLDP CONFIGURATION ...
Страница 240: ...240 CHAPTER 23 MSTP CONFIGURATION ...
Страница 272: ...272 CHAPTER 27 RIP CONFIGURATION ...
Страница 364: ...364 CHAPTER 29 IS IS CONFIGURATION ...
Страница 426: ...426 CHAPTER 31 ROUTING POLICY CONFIGURATION ...
Страница 442: ...442 CHAPTER 33 IPV6 RIPNG CONFIGURATION ...
Страница 466: ...466 CHAPTER 35 IPV6 IS IS CONFIGURATION ...
Страница 488: ...488 CHAPTER 36 IPV6 BGP CONFIGURATION ...
Страница 498: ...498 CHAPTER 37 ROUTING POLICY CONFIGURATION ...
Страница 540: ...540 CHAPTER 40 TUNNELING CONFIGURATION ...
Страница 552: ...552 CHAPTER 41 MULTICAST OVERVIEW ...
Страница 604: ...604 CHAPTER 43 MLD SNOOPING CONFIGURATION ...
Страница 628: ...628 CHAPTER 46 IGMP CONFIGURATION ...
Страница 699: ...Troubleshooting MSDP 699 4 Verify that the C BSR address is different from the anycast RP address ...
Страница 700: ...700 CHAPTER 48 MSDP CONFIGURATION ...
Страница 812: ...812 CHAPTER 57 DHCP SERVER CONFIGURATION ...
Страница 822: ...822 CHAPTER 58 DHCP RELAY AGENT CONFIGURATION ...
Страница 834: ...834 CHAPTER 61 BOOTP CLIENT CONFIGURATION ...
Страница 850: ...850 CHAPTER 63 IPV4 ACL CONFIGURATION ...
Страница 856: ...856 CHAPTER 64 IPV6 ACL CONFIGURATION ...
Страница 860: ...860 CHAPTER 65 QOS OVERVIEW ...
Страница 868: ...868 CHAPTER 66 TRAFFIC CLASSIFICATION TP AND LR CONFIGURATION ...
Страница 888: ...888 CHAPTER 69 PRIORITY MAPPING ...
Страница 894: ...894 CHAPTER 71 TRAFFIC MIRRORING CONFIGURATION ...
Страница 904: ...904 CHAPTER 72 PORT MIRRORING CONFIGURATION ...
Страница 930: ...930 CHAPTER 74 UDP HELPER CONFIGURATION ...
Страница 990: ...990 CHAPTER 79 FILE SYSTEM MANAGEMENT CONFIGURATION ...
Страница 1000: ...1000 CHAPTER 80 FTP CONFIGURATION ...
Страница 1020: ...1020 CHAPTER 82 INFORMATION CENTER CONFIGURATION ...
Страница 1038: ...1038 CHAPTER 84 SYSTEM MAINTAINING AND DEBUGGING ...
Страница 1046: ...1046 CHAPTER 85 DEVICE MANAGEMENT ...
Страница 1129: ...SSH Client Configuration Examples 1129 SwitchB ...
Страница 1130: ...1130 CHAPTER 88 SSH CONFIGURATION ...
Страница 1160: ...1160 CHAPTER 90 RRPP CONFIGURATION ...
Страница 1180: ...1180 CHAPTER 91 PORT SECURITY CONFIGURATION ...
Страница 1192: ...1192 CHAPTER 92 LLDP CONFIGURATION ...
Страница 1202: ...1202 CHAPTER 93 POE CONFIGURATION ...
Страница 1218: ...1218 CHAPTER 96 HTTPS CONFIGURATION ...