Cisco N5K-C5010P-BF Troubleshooting Guide - Page 60

Improper Configurations, Cannot pass frame size larger than 2300 bytes through switch - weight

Get Cisco N5K-C5010P-BF - Nexus 5010 Switch PDF manuals and user guides
UPC - 882658212208
View all Cisco N5K-C5010P-BF manuals
Add to My Manuals
Save this manual to your list of manuals

Page 60 highlights

Improper Configurations Chapter 4 Troubleshooting QoS Issues Send document comments to [email protected]. Table 4-1 Types of Policy Maps Policy Type QoS Queuing Network-QoS Function Attach Point • Define traffic classification • System QoS • Ingress interface • Strict Priority queue • System QoS • Deficit Weight Round Robin • Egress interface • Ingress interface • Define flow control mechanism (PAUSE or • System QoS tail drop) • MTU per class of service • Queue size • Marking With the basic process, the incoming packets are compared to the QoS classification rules that are defined by policy-map type qos. The packets are classified into 1 of 8 qos-groups. Next, the Network-QoS and Queuing policies are applied to the packets. The Queuing policy and the Network-QoS policy define actual QoS parameters for packets belonging to each qos-group. Note • The Queuing and Network-QoS policies match the qos-group (identified by policy-map type qos) instead of the actual packet headers. • When the same type of service policy is applied under the System QoS context and the interface level, the interface level service policy is preferred. • The queuing policy that is applied under the ingress interface is not applied locally. The queueing policy is the bandwidth allocation for a different class of service that is exchanged with its peer using the DCBX protocol. Improper Configurations Cannot pass frame size larger than 2300 bytes through switch Although the jumbo MTU has been configured for class-default, you cannot pass a frame size larger than 2300 bytes through the Nexus 5000 switch and the Nexus 2000 FEX. Possible Cause The CoS value may conflict with the existing MTU value. Solution CoS 7 is used internally for controlling traffic between the Nexus 5000 switch and the Nexus 2000 FEX. The MTU value for the traffic with CoS 7 is set to a fixed value. You must check that the incoming traffic is marked with CoS 7. Use any CoS value other than 7 to avoid this limitation. Cisco Nexus 5000 Series Troubleshooting Guide 4-2 OL-25300-01

  • 1
  • 2
  • 3
  • 4
  • 5
  • 6
  • 7
  • 8
  • 9
  • 10
  • 11
  • 12
  • 13
  • 14
  • 15
  • 16
  • 17
  • 18
  • 19
  • 20
  • 21
  • 22
  • 23
  • 24
  • 25
  • 26
  • 27
  • 28
  • 29
  • 30
  • 31
  • 32
  • 33
  • 34
  • 35
  • 36
  • 37
  • 38
  • 39
  • 40
  • 41
  • 42
  • 43
  • 44
  • 45
  • 46
  • 47
  • 48
  • 49
  • 50
  • 51
  • 52
  • 53
  • 54
  • 55
  • 56
  • 57
  • 58
  • 59
  • 60
  • 61
  • 62
  • 63
  • 64
  • 65
  • 66
  • 67
  • 68
  • 69
  • 70
  • 71
  • 72
  • 73
  • 74
  • 75
  • 76
  • 77
  • 78
  • 79
  • 80
  • 81
  • 82
  • 83
  • 84
  • 85
  • 86
  • 87
  • 88
  • 89
  • 90
  • 91
  • 92
  • 93
  • 94
  • 95
  • 96
  • 97
  • 98
  • 99
  • 100
  • 101
  • 102
  • 103
  • 104
  • 105
  • 106
  • 107
  • 108
  • 109
  • 110
  • 111
  • 112
  • 113
  • 114
  • 115
  • 116
  • 117
  • 118
  • 119
  • 120
  • 121
  • 122
  • 123
  • 124
  • 125
  • 126
  • 127
  • 128
  • 129
  • 130
  • 131
  • 132
  • 133
  • 134
  • 135
  • 136
  • 137
  • 138
  • 139
  • 140
  • 141
  • 142
  • 143
  • 144
  • 145
  • 146
  • 147
  • 148
  • 149
  • 150
  • 151
  • 152
  • 153
  • 154
  • 155
  • 156
  • 157
  • 158
  • 159
  • 160
  • 161
  • 162
Send document comments to [email protected].
4-2
Cisco Nexus 5000 Series Troubleshooting Guide
OL-25300-01
Chapter 4
Troubleshooting QoS Issues
Improper Configurations
With the basic process, the incoming packets are compared to the QoS classification rules that are
defined by policy-map type qos. The packets are classified into 1 of 8 qos-groups.
Next, the Network-QoS and Queuing policies are applied to the packets. The Queuing policy and the
Network-QoS policy define actual QoS parameters for packets belonging to each qos-group.
Note
•
The Queuing and Network-QoS policies match the qos-group (identified by policy-map type qos)
instead of the actual packet headers.
•
When the same type of service policy is applied under the System QoS context and the interface
level, the interface level service policy is preferred.
•
The queuing policy that is applied under the ingress interface is not applied locally. The queueing
policy is the bandwidth allocation for a different class of service that is exchanged with its peer using
the DCBX protocol.
Improper Configurations
Cannot pass frame size larger than 2300 bytes through switch
Although the jumbo MTU has been configured for class-default, you cannot pass a frame size larger than
2300 bytes through the Nexus 5000 switch and the Nexus 2000 FEX.
Possible Cause
The CoS value may conflict with the existing MTU value.
Solution
CoS 7 is used internally for controlling traffic between the Nexus 5000 switch and the Nexus 2000 FEX.
The MTU value for the traffic with CoS 7 is set to a fixed value. You must check that the incoming traffic
is marked with CoS 7. Use any CoS value other than 7 to avoid this limitation.
Table 4-1
Types of Policy Maps
Policy Type
Function
Attach Point
QoS
•
Define traffic classification
•
System QoS
•
Ingress interface
Queuing
•
Strict Priority queue
•
Deficit Weight Round Robin
•
System QoS
•
Egress interface
•
Ingress interface
Network-QoS
•
Define flow control mechanism (PAUSE or
tail drop)
•
MTU per class of service
•
Queue size
•
Marking
•
System QoS