{"id":942,"date":"2011-06-07T22:32:00","date_gmt":"2011-06-07T14:32:00","guid":{"rendered":"http:\/\/note.systw.net\/note\/?p=942"},"modified":"2023-11-07T22:47:01","modified_gmt":"2023-11-07T14:47:01","slug":"cisco-switch","status":"publish","type":"post","link":"https:\/\/systw.net\/note\/archives\/942","title":{"rendered":"Cisco Switch"},"content":{"rendered":"\n

switch\u9762\u7248\u524d\u7684\u71c8\u865f\u6709
system LED:<\/strong>\u986f\u793a\u7cfb\u7d71\u662f\u5426\u63a5\u6536\u5230\u96fb\u6e90\u4e26\u6b63\u5e38\u5de5\u4f5c
\u958b\u6a5fPOST\u6642,\u82e5\u7121\u71c8\u8868\u793a\u6e2c\u8a66\u57f7\u884c\u4e2d,\u7da0\u71c8\u8868\u793a\u6210\u529f,amber(\u9ec3\u8910\u8272)\u8868\u793apost\u5931\u6557
RPS(remote power supply) LED :<\/strong>\u986f\u793a\u662f\u4e0d\u662f\u5728\u4f7f\u7528\u9060\u7aef\u7684\u96fb\u6e90\u4f9b\u61c9
port LEDs:<\/strong>
\u958b\u6a5f\u6642\u82e5\u71c8\u865f\u70baamber\u8868\u793a\u6b63\u5728\u6aa2\u67e5,\u82e530sec\u5f8c\u8f49\u70ba\u7da0\u71c8\u8868\u793a\u6b63\u5e38,\u8f49amber\u71c8\u8868\u793a\u6709\u554f\u984c,\u82e5\u7121\u71c8\u8868\u793a\u8a72port\u5075\u6e2c\u4e0d\u5230\u9023\u7dda
\u900f\u904emode\u6309\u9215\u53ef\u9078\u64c7\u4ee5\u4e0b\u6a21\u5f0f
\u3000port mode
\u3000port status<\/p>\n\n\n\n

cisco switch\u5728auto-negotiation\u6703\u6839\u64dapriority table\u8868\u6c7a\u5b9aport mode,\u5982\u4e0b
Priority: Ethernet Mode
7: 100BASE-T2 (full duplex)
6: 100BASE-TX (full duplex)
5: 100BASE-T2
4: 100BASE-T4
3: 100BASE-TX
2: 10BASE-T (full duplex)
1: 10BASE-T
ps:\u672a\u6a19\u6ce8full duplex\u5247\u70bahalf duplex<\/p>\n\n\n\n

……<\/p>\n\n\n\n

Operations Within a Layer 2 Catalyst Switch<\/strong>
1
RX switch port
2
Ingress Queues
3
follows decisions are made simultaneously by independent portions of switching hardware
(TCAM)Security ACLs Inbound and Outbound
(TCAM)QoS ACLs Classification and Policing
(CAM)L2 Forwarding Table
4
Egress Queues
5
TX Switch Ports<\/p>\n\n\n\n

L2 forwarding table<\/strong>
\u5982\u540cmac table
Security ACLs<\/strong>
ACL can be used to identify frames according to their MAC addresses, protocol types (for non-IP frames), IP addresses, protocols, and Layer 4 port numbers.
The TCAM contains ACLs in a compiled form so that a decision can be made on whether to forward a frame in a single table lookup.
QoS ACLs<\/strong>
Other ACLs can classify incoming frames according to QoS parameters, to police or control the rate of traffic flows, and to mark QoS parameters in outbound frames.
The TCAM also is used to make these decisions in a single table lookup.<\/p>\n\n\n\n

………………<\/p>\n\n\n\n

cisco catalyst switch\u4f7f\u7528\u7684MLS\u6280\u8853\u5982\u4e0b<\/strong>
route caching(first-generation MLS)
topology-based (second-generation MLS)
ps:
only the topology-based is supported in the CiscoIOS Software-based switch families, such as the Catalyst 3750, 4500, and 6500
ps
switching methods\u7531\u5feb\u5230\u6162\u5206\u5225\u662f
dCEF, CEF, fast switching, process switching<\/p>\n\n\n\n

Route caching<\/strong>
requiring a RP(route processor) and a SE(switch engine).
\u3000The RP must process a traffic flow’s first packet to determine the destination.
\u3000The SE listens to the first packet and to the resulting destination, and sets up a “shortcut” entry in its MLS cache.
The SE forwards subsequent packets in the same traffic flow based on shortcut entries in its cache.
ps:
Even if this isn’t used to forward packets in Cisco IOS-based Catalyst switches, the technique generates traffic flow information and statistics.
ps:
This type of MLS also is known by the names
fast switching,Netflow LAN switching, flow-based\/demand-based switching, and “route once, switch many.”<\/p>\n\n\n\n

Topology-based\/CEF<\/strong> (utilizing specialized hardware.)
Layer 3 routing information builds and prepopulates a single database<\/strong> of the entire network topology.
1. This database, an efficient table lookup in hardware, is consulted so that packets can be forwarded at high rates.
2. The longest match found in the database is used as the correct Layer 3 destination.
3. As the routing topology changes over time, the database contained in the hardware can be updated dynamically with no performance penalty<\/p>\n\n\n\n

…….<\/p>\n\n\n\n

Operations Within a Multilayer Catalyst Switch<\/strong>
1
RX switch port
2
Ingress Queues
3
To forward packets using the simultaneous decision processes
\u4e3b\u8981\u5305\u62ec\u4ee5\u4e0b4\u500b\u540c\u6642\u88ab\u57f7\u884c
(TCAM)Security ACLs Inbound and Outbound
(TCAM)QoS ACLs Classification and Policing
(FIB)L3 Forwarding Table
(CAM)L2 Forwarding Table
4
L3 Packet Rewrite
5
Egress Queues
6
TX Switch Ports<\/p>\n\n\n\n


all these multilayer decisions are performed simultaneously in hardware
L2 forwarding table<\/strong>
\u5982\u540cmac table
If the frame contains a Layer 3 packet to be forwarded, the destination MAC address is that of a Layer 3 port on the switch.
In this case, the CAM table results are used only to decide that the frame should be processed at Layer 3.
(FIB)L3 forwarding table<\/strong>
The FIB table is consulted, using the destination IP address as an index.
The longest match in the table is found (both address and mask), and the resulting next-hop Layer 3 address is obtained.
The FIB also contains each next-hop entry’s Layer 2 MAC address and the egress switch port (and VLAN ID) so that further table lookups are not necessary.
\u6b04\u4f4d\u5305\u62ec\u4ee5\u4e0b
\u3000IP Address
\u3000Next-Hop IP Addr
\u3000Next-Hop MAC Addr
\u3000Egress Port
Security ACLs<\/strong>
Inbound and outbound access lists are compiled into TCAM entries so that decisions of whether to forward a packet can be determined as a single table lookup.
QoS ACLs<\/strong>
Packet classification, policing, and marking all can be performed as single table lookups in the QoS TCAM.<\/p>\n\n\n\n

rewritten<\/strong>
Because the contents of the Layer 3 packet (the TTL value) have changed, the Layer 3 header checksum must be recalculated.
And because both Layers 2 and 3 contents have changed, the Layer 2 checksum must be recalculated.
In other words, the entire Ethernet frame must be rewritten before it goes into the egress queue.
This also is accomplished efficiently in hardware<\/p>\n\n\n\n

Multilayer Switching Exceptions<\/strong>
it is flagged for further processing and sent or “punted” to the switch CPU for process switching
If a packet meets criteria such as the following:
\u25a0 ARP requests and replies
\u25a0 IP packets requiring a response from a router
(TTL has expired, MTU is exceeded, fragmentation is needed, and so on)
\u25a0 IP broadcasts that will be relayed as unicast
(DHCP requests, IP helper-address functions)
\u25a0 Routing protocol updates
\u25a0 Cisco Discovery Protocol packets
\u25a0 IPX routing protocol and service advertisements
\u25a0 Packets needing encryption
\u25a0 Packets triggering Network Address Translation (NAT)
\u25a0 Other non-IP and non-IPX protocol packets (AppleTalk, DECnet, and so on)<\/p>\n\n\n\n


………………………………………………………………………………….<\/p>\n\n\n\n

CAM(Content-Addressable Memory)<\/strong>
1. \u5982\u540cmac table
2. All Catalyst switch models use a CAM table for Layer 2 switching.
3. \u6b04\u4f4d\u5305\u62ec\u4ee5\u4e0b
\u3000MAC Address
\u3000Egress Port
\u3000VLAN
ps:\u904b\u4f5c\u65b9\u5f0f
1. The port of arrival and the VLAN both are recorded in the table, along with a timestamp<\/strong>.
2.1 If a MAC address learned on one switch port has moved to a different port, the MAC address and timestamp are recorded for the most recent arrival port. Then, the previous entry is deleted.
2.2 If a MAC address is found already present in the table for the correct arrival port, only its timestamp is updated<\/p>\n\n\n\n

CAM manage<\/strong>
To manage the CAM table space, stale entries (addresses that have not been heard from for a period of time) are aged out.
By default, idle CAM table entries are kept for 300 seconds<\/strong> before they are deleted<\/p>\n\n\n\n

MAC\u7570\u52d5\u904b\u4f5c\u65b9\u5f0f<\/strong>
case1
when a host’s MAC address is learned on one switch port, and then the host moves so that it appears on a different switch port
switch\u7684\u884c\u70ba\u5982\u4e0b
To avoid having duplicate CAM table entries, a switch purges(\u4e0d\u9700\u8981\u7b49\u5f85300\u79d2) any existing entries for a MAC address that has just been learned on a different switch port
case2
If a switch notices that a MAC address is being learned on alternating switch ports,
switch\u7684\u884c\u70ba\u5982\u4e0b
it generates an error message that flags the MAC address as “flapping”<\/strong> between interfaces.<\/p>\n\n\n\n


………………………………………..<\/p>\n\n\n\n

TCAM(Ternary Content-Addressable Memory)<\/strong>
The Catalyst IOS Software has two components that are part of the TCAM operation:
FM(Feature Manager)<\/strong>
After an access list has been created or configured, the FM software compiles, or merges, the ACEs into entries in the TCAM table.
The TCAM then can be consulted at full frame-forwarding speed.
SDM(Switching Database Manager)<\/strong>
You can partition the TCAM on some Catalyst switches into areas for different functions.
The SDM software configures or tunes the TCAM partitions, if needed.
(The TCAM is fixed on Catalyst 4500 and 6500 platforms and cannot be repartitioned.)<\/p>\n\n\n\n

ps:
compare<\/strong>
1.In traditional routing,
ACLs can match, filter, or control specific traffic.
Access lists are made up of one or more ACE or matching statements that are evaluated in sequential order.
Evaluating an access list can take up additional time, adding to the latency<\/strong> of forwarding packets.
2.In multilayer switches, however,
all the matching process that ACLs provide is implemented in hardware.
TCAM allows a packet to be evaluated against an entire access list in a single table lookup.
Most switches have multiple TCAMs so that both inbound and outbound security and QoS ACLs can be evaluated simultaneously<\/strong>, or entirely in parallel<\/strong> with a Layer 2 or Layer 3 forwarding decision.
ps:
access control entities (ACE)<\/p>\n\n\n\n

concept<\/strong>
The TCAM is an extension of the CAM table concept
TCAM also uses a table-lookup operation but is greatly enhanced to allow a more abstract operation
ex:
binary values (0s and 1s) make up a key into the table, but a mask value also is used to decide which bits of the key are actually relevant.
This effectively makes a key consisting of three input values: 0, 1, and X (don’t care) bit values-a three-fold or ternary combination.<\/p>\n\n\n\n

TCAM entries are composed of VMR(Value,Mask,Result) combinations
Values<\/strong>
be always 134-bit quantities, consisting of src and dst addr and other relevant protocol information – all patterns to be matched.
\u6b04\u4f4d\u6709:IP Protocol,IP ToS,Source IP,Src port,S Port LOU,Dest IP,Dest port,D Port LOU
The information concatenated to form the value depends on the type of access list
Values in the TCAM come directly from any address, port, or other protocol information given in an ACE.
\u3000Access List Type:<\/strong> Value and Mask Components, 134 Bits Wide (Number of Bits)
\u3000Ethernet:<\/strong> Source MAC (48), destination MAC (48), Ethertype (16)
\u3000ICMP:<\/strong> Source IP (32), destination IP (32), protocol (16), ICMP code (8), ICMP type (4), IP type of service (ToS) (8)
\u3000Extended IP using TCP\/UDP:<\/strong> Source IP (32), destination IP (32), protocol (16), IP ToS (8), source port (16), source operator (4), destination port (16),destination operator (4)
\u3000Other IP:<\/strong> Source IP (32), destination IP (32), protocol (16), IP ToS (8)
\u3000IGMP:<\/strong> Source IP (32), destination IP (32), protocol (16), IP ToS (8),IGMP message type (8)
\u3000IPX:<\/strong> Source IPX network (32), destination IPX network (32), destination node (48), IPX packet type (16)
Masks<\/strong>
are 134-bit quantities, in exactly the same format, or bit order, as the values.
Masks select only the value bits of interest; a mask bit is set to exactly match a value bit or is not set for value bits that do not matter.
The masks used in the TCAM stem from address or bit masks in ACEs
Results<\/strong>
are numeric values that represent what action to take after the TCAM lookup occurs.
Whereas traditional access lists offer only a permit or deny result, TCAM lookups offer a number of possible results or actions.
ex:
the result can be a permit or deny decision, an index value to a QoS policer, a pointer to a next-hop routing table, and so on.<\/p>\n\n\n\n

The TCAM always is organized by masks, where each unique mask has eight value patterns associated with it.
ex:
the Catalyst 6500 TCAM (one for security ACLs and one for QoS ACLs) holds up to 4096 masks and 32,768 value patterns.
The trick is that each of the mask-value pairs is evaluated simultaneously, or in parallel, revealing the best or longest match in a single table lookup.<\/p>\n\n\n\n

Port Operations in TCAM<\/strong>
1. If an ACE has a port operator
ex:( such as gt, lt, neq, or range,)
access-list 100 deny udp any 192.168.5.0 0.0.0.255 gt 1024
access-list 100 deny udp any 192.168.199.0 0.0.0.255 range 1024 2047
the FM software compiles the TCAM entry to include the use of the operator and the operand in a LOU(logical operation unit) register.<\/strong>
Only a limited number of LOUs are available in the TCAM
ex:
LOU register pairs
A.1( gt 1024) , A.2( )
B.1(range start 1024) , B.2(range end 2047)
ps:
If there are more ACEs with comparison operators than there are LOUs, the FM must break up the ACEs into multiple ACEs with only regular matching (using the eq operator).
2.The FM checks all ACEs for Layer 4 operation and places these into LOU register pairs.
3.These can be loaded with operations, independent of any other ACE parameters.
4.The LOU contents can be reused if other ACEs need the same comparisons and values.
5.After the LOUs are loaded, they are referenced in the TCAM entries that need them.
ps:
A finite number (actually, a rather small number) of LOUs are available in the TCAM, so the FM software must use them carefully.<\/p>\n\n\n\n

TCAM resources<\/strong>
TCAMs have a limited number of 1)usable mask, 2)value pattern, and 3)LOU entries.
If access lists grow to be large or many Layer 4 operations are needed, the TCAM tables and registers can overflow.<\/strong>
If that happens while you are configuring an ACL, the switch will generate syslog messages that flag the TCAM overflow situation<\/strong> as it tries to compile the ACL into TCAM entries.<\/p>\n\n\n\n

\u9032\u5165punting(\u5e73\u677f\u50b3\u8f38)<\/strong>
\u7576TCAM\u7121\u6cd5\u7528\u4f86\u8f49\u9001\u8cc7\u6599\u6d41,\u7cfb\u7d71\u6703\u81ea\u52d5\u7528CPU\u4f86\u8655\u7406,\u4f46\u8655\u7406\u6548\u80fd\u6709\u9650
\u53ef\u80fd\u539f\u56e0:TCAM\u5bb9\u91cf\u5df2\u6eff
\u89e3\u6c7a\u65b9\u5f0f:\u63db\u6210\u9ad8\u5bb9\u91cfTCAM\u4ea4\u63db\u5668,\u6216\u6e1b\u5c11TCAM\u4e2d\u9805\u76ee
ps:\u53ef\u6839\u64da\u8a2d\u5099\u7684\u67e5\u9a57\u6307\u4ee4\u78ba\u8a8dTCAM\u4f7f\u7528\u7387
ps:punting\u7684\u60c5\u6cc1\u9084\u5305\u62ec,\u786c\u9ad4\u672a\u652f\u63f4\u7684\u529f\u80fd,\u9060\u7aef\u767b\u5165,\u7b49… <\/p>\n\n\n\n

…………………………<\/p>\n\n\n\n

\u5728switch\u8a2d\u5b9a\u9810\u8a2d\u9598\u9053
(config)#ip default-gateway < ip><\/strong>
\u82e5\u5c01\u5305\u4e0d\u77e5\u5f80\u90a3\u9001,\u5247\u9001\u53bb\u9810\u8a2d\u9598\u9053
ps:\u82e5\u60f3\u8b93switch\u5f9e\u9060\u7aef\u9023\u5165\u5efa\u8b70\u8a2d\u5b9a,\u4ee5\u5354\u52a9\u56de\u61c9\u62b5\u9054\u9060\u7aef<\/p>\n\n\n\n


\u5728multilayer switch\u4e0a\u555f\u52d5route\u529f\u80fd
(config)#ip routing<\/strong><\/p>\n\n\n\n


\u4ee5macro\u547d\u4ee4\u6307\u5b9a\u55ae\u4e00\u4e3b\u6a5f\u4ecb\u9762
Switch(config-if)# switchport host<\/strong>
\u6703\u767c\u751f\u4ee5\u4e0b\u3000
switchport mode will be set to access
spanning-tree portfast will be enabled
channel group will be disabled<\/p>\n\n\n\n


multilayer switch interface mode<\/strong>
Layer 2 mode:layer2\u4ecb\u9762,\u4e00\u822cswitch \u4ecb\u9762
Layer 3 mode:layer3\u4ecb\u9762,\u53ef\u8a2dip,\u6709\u652f\u63f4\u7b2c\u4e09\u5c64\u7684switch\u4ecb\u9762
ps:
every switch port on
\u3000most Catalyst switch: is a Layer 2 interface,
\u3000Catalyst 6500: is a Layer 3 interface<\/p>\n\n\n\n


\u8a2d\u5b9amultilayer switch interface\u70balayer2 mode
Switch(config-if)# switchport<\/strong><\/p>\n\n\n\n

\u8a2d\u5b9amultilayer switch interface\u70balayer3 mode
Switch(config-if)# no switchport<\/strong>
Switch(config-if)# ip address < ip > mask [secondary]<\/strong>
ps:
the EtherChannel can also become a Layer 3 port.
ps:
\u82e5layer1,2\u90fd\u7121\u6cd5\u4f5c\u696d\u6642\uff0c\u5247\u8a72\u4ecb\u9762\u8996\u70ba\u95dc\u9589\u72c0\u614b\u3000
\u8a72\u4ecb\u9762\u7121\u6cd5\u53c3\u8207STP,DTD\u7b49\u4ea4\u63db\u5354\u5b9a<\/p>\n\n\n\n

\u5728\u6307\u5b9aVLAN\u5167\u8a2d\u5b9aSVI
Switch(config)# interface vlan < vlan-id>
Switch(config-if)# ip address < ip > mask [secondary]<\/strong>
Switch(config-if)# no shutdown<\/strong>
ps:\u82e5vlan\u4e2d\u6c92\u6709\u4efb\u4f55\u4ecb\u9762\u904b\u4f5c\uff0c\u5247SVI\u88ab\u8996\u70ba\u95dc\u9589\u72c0\u614b<\/p>\n\n\n\n

Verifying interface mode
# show interface < interface > switchport<\/strong>
\u8f38\u51fa\u7684Switchport\u986f\u793a:
\u3000Disabled: \u8a72\u4ecb\u9762\u70balayer3 mode
\u3000Enabled: \u8a72\u4ecb\u9762\u70balayer2 mode
ps:
router\u4ecb\u9762\u9810\u8a2d\u70baDisabled,switch\u4ecb\u9762\u548cSVI\u9810\u8a2d\u70baEnabled
ps:
\u82e5SVI\u986f\u793aswitchport:Disabled\u5247\u53ef\u80fd\u6709\u4ee5\u4e0b\u539f\u56e0
the interface is disabled with the shutdown command
the VLAN itself has not been defined on the switch.
ps:
show interface switchport\u70ba\u4f8b,\u756b\u9762\u5927\u81f4\u5982\u4e0b
namee: Gi4\/2
Switchport: Enabled
Administrative Mode: trunk
Operational Mode: trunk \/\/\u82e5\u70badown\u8868\u793a\u4ecb\u9762\u6c92\u5728\u904b\u4f5c
[omitted]<\/p>\n\n\n\n


………………………<\/p>\n\n\n\n


to configure static CAM table entries
(config)# mac address-table static < mac-address> vlan interface < interface><\/strong>
\u56e0\u4e0d\u7528\u6bcf\u6b21\u90fdflood\u4f86\u5b78\u7fd2\u52d5\u614b\u4f4d\u7f6e,\u56e0\u6b64\u53ef\u7bc0\u7701\u983b\u5bec
ex:\u8a2d\u5b9a2950switch fa0\/5\u662f\u75311111.1111.1111\u7684mac\u4f4d\u7f6e\u548cvlan1\u5b58\u53d6
2950(config)#mac-address-table static 1111.1111.1111 vlan 1 int fa0\/5
ps:\u65e9\u671f\u82e5\u6b64mac\u82e5\u51fa\u73fe\u5728\u4e0d\u540c\u7684PORT,\u5247\u6b64\u6a5f\u5668\u7121\u6cd5\u4e0a\u7db2
ps:1900(config)#mac-address-table permanent<\/p>\n\n\n\n

to clear CAM table entries
Switch# clear mac address-table dynamic [address < mac> | interface < interface> | vlan < vlan-id>]<\/strong>
\u82e5\u4e0d\u60f3\u7b49\u5f85\u52d5\u614b\u4f4d\u7f6e\u6642\u9593\u5230\u6642\u624d\u88ab\u79fb\u9664\u53ef\u624b\u52d5\u7acb\u523b\u79fb\u9664<\/p>\n\n\n\n

to change the CAM table entries aging-time
Switch(config)# mac address-table aging-time < seconds><\/strong>
default,300sec<\/p>\n\n\n\n

To view the contents of the CAM table
#show mac address-table dynamic [address < mac> | interface < interface> | vlan < vlan-id>]<\/strong>
[address < mac>]: to specify a single MAC address
[interface < interface>] to see addresses that have been learned on a specific interface
[vlan < vlan-id>] to see addresses that have been learned on a specific vlan
ps:\u90e8\u4efd\u8a2d\u5099\u9700\u6539\u7528show mac-address-table
ps:
to find the learned location of the host with MAC address 0050.8b11.54da
#show mac address-table dynamic address 0050.8b11.54da
Mac Address Table
——————————————–
Vlan Mac Address Type Ports
—- ———– —- —–
54 0050.8b11.54da DYNAMIC Fa1\/0\/1
Total Mac Addresses for this criterion: 1
ex:
To see all the MAC addresses that are currently found on interface GigabitEthernet1\/0\/29
Switch# show mac address-table dynamic interface gigabitethernet1\/0\/29
Mac Address Table
———————————————–
Vlan Mac Address Type Ports
—- ———– —- —–
537 0013.7297.3d4b DYNAMIC Gi1\/0\/29
Total Mac Addresses for this criterion: 1<\/p>\n\n\n\n

ps:
\u8f38\u51fa\u7121\u7d50\u679c\u7684\u53ef\u80fd\u6709\u4ee5\u4e0b
1. showing nothing about the interface and VLAN where the MAC address is found.
2. the host has not sent a frame that the switch can use for learning its location,or something odd is going on.
3. the host is using two network interface cards (NIC) to load balance traffic;one NIC is only receiving traffic, whereas the other is only sending. Therefore, the switch never hears and learns the receiving-only NIC address<\/p>\n\n\n\n


To see the CAM table’s size
Switch# show mac address-table count<\/strong>
MAC address totals are shown for each active VLAN on the switch.
This can give you a good idea of the size of the CAMtable and how many hosts are using the network.
ps:
Switch# show mac address-table count
Mac Entries for Vlan 1:
—————————
Dynamic Address Count : 0
Static Address Count : 0
Total Mac Addresses : 0
Mac Entries for Vlan 2:
—————————-
Dynamic Address Count : 89
Static Address Count : 0
Total Mac Addresses : 89
Mac Entries for Vlan 580:
—————————–
Dynamic Address Count : 600
Static Address Count : 0
Total Mac Addresses : 600
Total Mac Address Space Available: 4810<\/p>\n","protected":false},"excerpt":{"rendered":"

switch\u9762\u7248\u524d\u7684\u71c8\u865f\u6709system LED:\u986f\u793a\u7cfb\u7d71\u662f\u5426 …<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"fifu_image_url":"","fifu_image_alt":"","_jetpack_memberships_contains_paid_content":false,"footnotes":"","jetpack_publicize_message":"","jetpack_publicize_feature_enabled":true,"jetpack_social_post_already_shared":false,"jetpack_social_options":{"image_generator_settings":{"template":"highway","default_image_id":0,"font":"","enabled":false},"version":2}},"categories":[34],"tags":[],"class_list":["post-942","post","type-post","status-publish","format-standard","hentry","category-cisco-layer2"],"jetpack_publicize_connections":[],"jetpack_featured_media_url":"","jetpack_sharing_enabled":true,"_links":{"self":[{"href":"https:\/\/systw.net\/note\/wp-json\/wp\/v2\/posts\/942","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/systw.net\/note\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/systw.net\/note\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/systw.net\/note\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/systw.net\/note\/wp-json\/wp\/v2\/comments?post=942"}],"version-history":[{"count":0,"href":"https:\/\/systw.net\/note\/wp-json\/wp\/v2\/posts\/942\/revisions"}],"wp:attachment":[{"href":"https:\/\/systw.net\/note\/wp-json\/wp\/v2\/media?parent=942"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/systw.net\/note\/wp-json\/wp\/v2\/categories?post=942"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/systw.net\/note\/wp-json\/wp\/v2\/tags?post=942"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}