troubleshooting series comes again, in today troubleshooting case, we will introduce: Error Packets Are Transmitted on Electrical Interfaces of Switches, or Interfaces on Switches Connected to PCs Alternate Between Up and Down Randomly
Physical Network Topology
Figure 1-1 Network where a fauilre occurs
Fault Description
1. Error packets are transmitted on the switch's electrical interface that works in half-duplex mode through negotiation.
2. The switch's interface connected to the PC alternates between Up and Down randomly.
Configuration Files
# SwitchA(R10U36-S3700)
#
!Software Version V100R006C05
sysname R10U36-S3700
#
vlan batch 20 30 103 220
#
lldp enable
#
acl number 3000
rule 5 permit icmp source 2.1.1.1 0 destination 1.1.1.1 0
rule 10 permit icmp source 1.1.1.1 0 destination 2.1.1.1 0
#
aaa
authentication-scheme default
authorization-scheme default
accounting-scheme default
domain default
domain default_admin
local-user admin password cipher %@%@^bs5*JFbe4(a,S9*1RbKTA!$%@%@
local-user admin privilege level 15
local-user admin service-type telnet terminal ssh http
#
interface Ethernet0/0/23
port link-type access
port default vlan 20
auto speed 10
#
interface Ethernet0/0/25
#
interface NULL0
#
ip route-static 0.0.0.0 0.0.0.0 10.220.6.1
#
return
#SwitchB(R10U11-S9706)
!Software Version V200R008C00SPC500
#
sysname R10U11-S9706
#
vlan batch 20
#
lldp enable
#
clock timezone UTC add 00:00:00
#
icmp-reply fast
#
diffserv domain default
#
drop-profile default
#
aaa
authentication-scheme default
authorization-scheme default
accounting-scheme default
domain default
domain default_admin
local-user admin password irreversible-cipher
%^%#rr]KD+}\>0O"Fx#[|gf+^1<\XP#EtT/S_"IueGEYOhlZ;jkzh=F!N2IWP]<Q%^%#
local-user admin privilege level 15
local-user admin service-type terminal ssh http
#
interface Vlanif20
ip address 1.1.1.1 255.255.255.0
#
interface Eth-Trunk100
#
interface Ethernet0/0/0/0
ip address 10.220.7.128 255.255.254.0
#
interface GigabitEthernet1/1/1/23
port link-type access
port default vlan 20
undo negotiation auto
speed 10
#
ip route-static 0.0.0.0 0.0.0.0 10.220.6.1
ip route-static 2.1.1.0 255.255.255.0 1.1.1.2
#
return
Troubleshooting Location
Troubleshooting Procedure
Step 1 Check the running status of the Ethernet 0/0/23 which conneted to the SwitchB.
Run the display interface XXXcommand, and it is found that the interface works in half-duplex mode through auto-negotiation, indicating that the peer end must work in forcible mode.
<HUAWEI> display interface
gigabitethernet 0/0/23
Ethernet 0/0/23 current state :
UP
Line protocol current state :
UP
Description:HUAWEI, Quidway Series, Ethernet0/0/23
Interface
Switch Port, PVID : 20, TPID : 8100(Hex), The Maximum Frame Length
is 1600
IP Sending Frames' Format is PKTFMT_ETHNT_2, Hardware address is 38bc-01ec-9520
Port Mode: COMMON COPPER
Speed : 10, Loopback: NONE
puplex: HALF, Negotiation: ENABLE
Mdi : AUTO
...
Solution: Modify the auto-negotiation mode on both ends to be consistent.
<R10U11-S9706> system-view
[R10U11-S9706] interface gigabitethernet 1/1/1/23
[R10U11-S9706] negotiation auto
And then it is found that the ethernet interface connected to the PC frequently alternates between up and down states.
Step 2 Check the configuration on the PC after confirming that the cable, module, negotiation mode, rate, and device hardware at both ends of the switch are intact.
And then it is found that the WOL function was configured on the PC and the PC enters the standby or sleep state.
Figure 1-2 WOL enabled on the PC
