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How to Troubleshoot Connectivity on 200-Series

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TitleHow to Troubleshoot Connectivity on 200-Series
Objective
Show how to troubleshoot connectivity on a 200-Series 
Environment
200-Series
Procedure
If 200-Series Cannot Ping a Connected Device
  • Check the status of the port
                         show port 0/1

                 Admin     Physical   Physical   Link   Link    LACP   Actor
Intf      Type   Mode      Mode       Status     Status Trap    Mode   Timeout
--------- ------ --------- ---------- ---------- ------ ------- ------ --------
0/1              Enable    Auto       1000 Full  Up     Enable  Enable long
  • Check the SAT to verify the MAC of the next hop is learned in the correct VLAN
(Extreme 220)#show mac-addr-table  interface 1/0/1
MAC Address         VLAN ID      Status
-----------------            ---------       ------------
00:04:96:98:88:62      52           Learned
00:E0:2B:00:00:01     52           Learned
  • If the MAC is learned in the wrong VLAN check the VLAN config (above) 
  • If no mac is learned use show  interface to verify traffic is being transmitted and received
(Extreme 220) #show interface 1/0/1

Packets Received Without Error................. 1615816398
Packets Received With Error.................... 0
Broadcast Packets Received..................... 1129557813
Receive Packets Discarded...................... 0
Packets Transmitted Without Errors............. 503514248
Transmit Packets Discarded..................... 0
Transmit Packet Errors......................... 0
Collision Frames............................... 0
Number of link down events..................... 3
Load Interval.................................. 300
Bits Per Second Received....................... 200
Bits Per Second Transmitted.................... 576
Packets Per Second Received.................... 0
Packets Per Second Transmitted................. 0
Percent Utilization Received................... 0%
Percent Utilization Transmitted................ 0%
Time Since Counters Last Cleared............... 19 day 23 hr 10 min 7 sec
  • Clear the statistics if desired
(Extreme 220) #clear  counters  1/0/1
Are you sure you want to clear the port stats? (y/n) y
Port Stats Cleared.
  • Verify the IP to MAC binding is correct in the ARP cache
(Extreme 220) #show arp
Age Time (seconds)............................. 1200
Response Time (seconds)........................ 1
Retries........................................ 4
Cache Size..................................... 2048
Dynamic Renew Mode ............................ Disable
Total Entry Count Current / Peak .............. 2 / 2
Static Entry Count Configured / Active / Max .. 0 / 0 / 16

  IP Address         MAC Address          Interface        Type        Age
---------------           -----------------           --------------     --------       -----------
192.168.52.1       00:04:96:98:88:62    0/4/2           Gateway    0h  3m 23s
192.168.52.254   00:04:96:9F:B9:13   0/4/2           Local          n/a
  • Verify the IP to MAC binding is correct
  • If the IP is associated to  an incorrect MAC it may indicate a duplicate IP
  • No entry may indicate a layer two issuelike misconfigured VLAN or cable connected to  the wrong port
  • Check the state of the layer three interface
(Extreme 220) >show ip interface brief
Interface    State    IP Address          IP Mask            TYPE            Method
-----------     -----      ---------------       ---------------       ---------------   ---------------
vlan 53      Down   192.168.53.1      255.255.255.0   Primary         Manual
vlan 52      Up        192.168.52.254  255.255.255.0   Primary         Manual
  • Interface will be down if there is no link, no VLAN configured, or they are administratively shut down
What Can Ping Tell Us?
  • Ping the device and note the error
(Extreme 220) #ping 192.168.52.1
Pinging 192.168.52.1 with 0 bytes of data:

Reply From 192.168.52.254: Destination Unreachable.
Reply From 192.168.52.254: Destination Unreachable.
Reply From 192.168.52.254: Destination Unreachable.

----192.168.52.1 PING statistics----
3 packets transmitted, 0 packets received, 100% packet loss

 
  • The destination unreachable error coming from the 200-Series own IP 192.168.52.254 indicates that the subnet location is known but the device is not replying
  • Other routers may send ICMP messages indicating why the ping failed
(Extreme 220) #ping 203.0.113.1
Pinging 203.0.113.1 with 0 bytes of data:
Reply From 10.58.200.38: Destination Unreachable.
Reply From 10.58.200.38: Destination Unreachable.
Reply From 10.58.200.38: Destination Unreachable.
----203.0.113.1 PING statistics----
3 packets transmitted, 0 packets received, 100% packet loss
round-trip (msec) min/avg/max = <1/<1/<1
  • The Default Gateway 10.58.200.38 is indicating  no route  to the destination. 
  • The 200-Series is sending the ping to the default gateway because the route is not  in its routing table which may indicate a problem with the dynamic routing protocol, or  misconfigured or missing static route
  • If users can ping their gateway but not communicate passed the 200-Series use the ping source command to source the ping from the same interfaces used for the clients gateway

(Extreme 220) #ping 192.168.52.1 source 192.168.53.254
Pinging 192.168.52.1 with 0 bytes of data:

Reply From 192.168.52.1: icmp_seq = 0. time= 2 msec.
Reply From 192.168.52.1: icmp_seq = 1. time= 1 msec.
Reply From 192.168.52.1: icmp_seq = 2. time= 1 msec.


----192.168.52.1 PING statistics----
3 packets transmitted, 3 packets received, 0% packet loss
round-trip (msec) min/avg/max = 1/1/2
  • If the source command fails it indicates the upstream router does not have a route back to the client  subnet
  • If it works it indicates the client has an incorrectly configured default gateway
  • Use Traceroute to Determine the Routers in the Path to the Destination
 
(Extreme 220) #traceroute  192.168.44.1
   Traceroute to 192.168.44.1 ,30 hops max 0 byte packets:
1  192.168.52.1       <1  ms    <1  ms    <1  ms  
2  0.0.0.0            *         *         *       
3  0.0.0.0            *         *       
Hop Count = 3 Last TTL = 3 Test attempt = 8 Test Success = 3
  • Check the Route Table
(Extreme 220) #show ip route
Route Codes: C - Connected, S - Static
S      1.1.1.1/32 [1/0] via 192.168.52.1,   0/4/2
R      192.168.50.0/24 [120/2] via 192.168.52.1,   00h:00m:30s,  0/4/2
C      192.168.52.0/24 [0/0] directly connected,   0/4/2
S      198.0.0.0/8 [1/0] via 192.168.52.1,   0/4/2
R      198.51.100.0/24 [120/2] via 192.168.52.1,   00h:00m:30s,  0/4/2
  • Check to verify  routes to destinations that cannot be pinged
  • Check the letter in the left column to determine the protocol by which the route was learned
  • If the router table has only connected routes and not R RIP routes are in the table it indicates an issue with rip configuration or the connection to the RIP neighbor
  • Check the timestamp of routes if you suspect a route has failed intermittently
  • If the connected routes have a longer age than dynamic   routes it indicates a RIP problem
  • If the RIP and Connected routes are  the same age then the physical layer failed
  • If a static route is configured but not in the route table it indicates the interface to the destination is down
  • If latency is reported use the following  command to check, Ethernet errors, port utilization, pause frames received and transmitted, and statistics for layer two protocols
show interface ethernet  0/1

Total Packets Received (Octets)................ 228253391
Packets Received 64 Octets..................... 645616
Packets Received 65-127 Octets................. 919057
Packets Received 128-255 Octets................ 41541
Packets Received 256-511 Octets................ 308869
Packets Received 512-1023 Octets............... 356
Packets Received 1024-1518 Octets.............. 145
Packets Received > 1518 Octets................. 0
Packets RX and TX 64 Octets.................... 658199
Packets RX and TX 65-127 Octets................ 1259378
Packets RX and TX 128-255 Octets............... 67421
Packets RX and TX 256-511 Octets............... 313324
Packets RX and TX 512-1023 Octets.............. 603
Packets RX and TX 1024-1518 Octets............. 2348
Packets RX and TX 1519-2047 Octets............. 0
Packets RX and TX 2048-4095 Octets............. 0
Packets RX and TX 4096-9216 Octets............. 0

Total Packets Received Without Errors.......... 1915584
Unicast Packets Received....................... 75963
Multicast Packets Received..................... 229839
Broadcast Packets Received..................... 1609782

Receive Packets Discarded...................... 0

Total Packets Received with MAC Errors......... 0
Jabbers Received............................... 0
Fragments Received............................. 0
Undersize Received............................. 0
Alignment Errors............................... 0
FCS Errors..................................... 0
Overruns....................................... 0

Total Received Packets Not Forwarded........... 1406539
802.3x Pause Frames Received................... 0
Unacceptable Frame Type........................ 1406539

Total Packets Transmitted (Octets)............. 51402935
Packets Transmitted 64 Octets.................. 12583
Packets Transmitted 65-127 Octets.............. 340321
Packets Transmitted 128-255 Octets............. 25880
Packets Transmitted 256-511 Octets............. 4455
Packets Transmitted 512-1023 Octets............ 247
Packets Transmitted 1024-1518 Octets........... 2203
Packets Transmitted > 1518 Octets.............. 0
--More-- or (q)uit                  Max Frame Size................................. 1518
Maximum Transmit Unit.......................... 1500

Total Packets Transmitted Successfully......... 385689
Unicast Packets Transmitted.................... 51202
Multicast Packets Transmitted.................. 333060
Broadcast Packets Transmitted.................. 1427

Transmit Packets Discarded..................... 0

Total Transmit Errors.......................... 0

Total Transmit Packets Discarded............... 0
Single Collision Frames........................ 0
Multiple Collision Frames...................... 0
Excessive Collision Frames..................... 0

802.3x Pause Frames Transmitted................ 0
GVRP PDUs received............................. 0
GVRP PDUs Transmitted.......................... 0
GVRP Failed Registrations...................... 0
GMRP PDUs Received............................. 0
GMRP PDUs Transmitted.......................... 0
GMRP Failed Registrations...................... 0

STP BPDUs Transmitted.......................... 0
STP BPDUs Received............................. 0
RSTP BPDUs Transmitted......................... 0
RSTP BPDUs Received............................ 0
MSTP BPDUs Transmitted......................... 293917
MSTP BPDUs Received............................ 0
SSTP BPDUs Transmitted......................... 0
SSTP BPDUs Received............................ 0

EAPOL Frames Transmitted....................... 0
EAPOL Start Frames Received.................... 0

Load Interval.................................. 300
Bits Per Second Received....................... 3344
Bits Per Second Transmitted.................... 952
Packets Per Second Received.................... 4
Packets Per Second Transmitted................. 1
Percent Utilization Received................... 0%
Percent Utilization Transmitted................ 0%

Time Since Counters Last Cleared............... 6 day 19 hr 18 min 53 sec


 
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