longan table: L3_PREFIX_ROUTE_IPUC
Details
- Name
- L3_PREFIX_ROUTE_IPUC
- Feature
- LAYER_3_ROUTING
- Type
- 2
- Entries
- 512
- Data width
- 352
- Control register
- TBL_ACCESS_CTRL_1
- Data register
- TBL_ACCESS_DATA_1
Description
Main table for L3 prefix routes.
Entries can be either IPv4 Unicast, Multicast or IPv6 UC/MC. Entries in the table are stored in an associative memory and can be directly looked up by the hardware. The driver can look up entries via L3_HW_LU_KEY_CTRL
Note: this table space holds a union of entries of table types L3_PREFIX_ROUTE_*, which are distinguished by the entry type values, which are always at the same register position in the table data. See there for the different types.
Fields
| Name | LSB | Bits | Description |
|---|---|---|---|
| VALID | 351 | 1 |
1: The routing entry is valid, 0: it is invalid and ignored |
| ENTRY_TYPE | 349 | 2 |
Type of the table entry: 0: IPv4 Unicast route 1: IPV4 Multicast route 2: IPv6 Unicast route 3: IPv6 Multicast route |
| IP | 192 | 32 |
The IPv4 address of the routed network or host |
| BMSK_ENTRY_TYPE | 189 | 2 |
Probably a bit-mask for the ENTRY_TYPE, always set to 0x3 in the SDK |
| BMSK_IP | 32 | 32 |
Network bit-mask for the routed network IP address E.g 0xffffff00 (255.255.255.0) when the routed IP-address is a /24 network. |
| HIT | 22 | 1 |
|
| HOST_ROUTE | 21 | 1 |
Set to 1 for a /32 route (a route to a particular host) |
| DFLT_ROUTE | 20 | 1 |
Set to 1 for a /0 route (default route) |
| ACTION | 18 | 2 |
0: FORWARD, 1: TRAP2CPU, 2:COPY2CPU, 3: DROP |
| NH_IDX | 7 | 11 |
An index into the L3_NEXTHOP table. |
| TTL_DEC | 6 | 1 |
Decrease the TTL of the routed packet. |
| TTL_CHK | 5 | 1 |
Drop the packet if the TTL is 0. |
| DST_NULL_INTF | 4 | 1 |
The destination interface is the NULL interface It is not clear what the difference to merely dropping the packet is, but NULL-interfaces are used for access control mechanisms The SDK sets up several NULL interfaces for the 802.x support. |
| QOS_AS | 3 | 1 |
QOS_PRI valid (1) nor not valid |
| QOS_PRI | 0 | 3 |
New quality of Service priority for a packet routed by this route |