In Cisco networks, there are four main types of interfaces in the final stable state of a switch in a LAN: Access/trunk/multi/dot1q-tunnel.
1, Access: Mainly used to access terminal equipment, such as PC, server, print server and so on.
2, Trunk: Mainly used to connect other switches, in order to host multiple VLANs on the line.
3. Multi: Hosts multiple VLANs in one line, but unlike trunks, it does not label the data being hosted. It is mainly used to access servers that support multiple VLANs or some network analysis devices. This type of interface is not currently used at all, and in Cisco's network devices, such interfaces are largely unsupported.
4, Dot1q-tunnel: Used in the Q-in-q tunnel configuration.
Cisco network devices support the working state of a dynamically negotiated port, which provides some convenience for the implementation of network devices (but is not recommended to use dynamic methods). Cisco dynamic negotiation protocol is developed from the initial DISL (Cisco Private Protocol) to DTP (public agreement). Depending on how the dynamic protocol is implemented, the Cisco network Device interface is mainly divided into the following modes:
1. Switchport mode access: Forces the interface to become an access interface and can actively negotiate with the other person to entice the other person into Access mode.
2, Switchport mode dynamic desirable: active and to negotiate the possibility of becoming trunk interface, if the Neighbor interface mode is one of Trunk/desirable/auto, then the interface will become the trunk interface work. If trunk mode cannot be formed, then work in Access mode. This mode is now the default mode for the switch.
3. Switchport mode dynamic Auto: Only the neighbor switch becomes the trunk interface when it actively negotiates with itself, so it is a passive mode and becomes trunk when the neighbor interface is one of trunk/desirable. If trunk mode cannot be formed, then work in Access mode.
4, Switchport mode trunk: Force the interface to become trunk interface, and actively entice the other side to become trunk mode, so when the neighbor switch interface is Trunk/desirable/auto will become trunk interface.
5, Switchport Nonegotiate: Strictly speaking, this is not a kind of interface mode, its role is only to prevent the switch interface issued DTP packets, it must be used with Switchport mode trunk or Switchport mode access.
6. Switchport Mode dot1q-tunnel: Configure the switch interface as a tunnel interface (non-trunk) to form an asymmetric link with the trunk interface of the user switch
This article is from the "Sky" blog, please be sure to keep this source http://haikuotiankong.blog.51cto.com/633188/1695329
Cisco switch interface Mode fine Solutions