询问下基于子接口流量如何查看

R82版本：

traffic-statistic enable命令用来开启以太网子接口的报文统计功能。
# 开启三层以太网子接口GigabitEthernet3/1/1.1的报文统计功能。
<Sysname> system-view
[Sysname] interface gigabitethernet 3/1/1.1
[Sysname-GigabitEthernet3/1/1.1] traffic-statistic enable

# 查看三层以太网子接口GigabitEthernet3/1/1.1的运行状态和相关信息。

<Sysname> display interface gigabitethernet 3/1/1.1

GigabitEthernet3/1/1.1

Current state: DOWN

Line protocol state: DOWN

Description: GigabitEthernet3/1/1.1 Interface

Bandwidth: 1000000 kbps

Maximum transmission unit: 1500

Internet protocol processing: Disabled

IP packet frame type: Ethernet II, hardware address: 80f6-fe00-f4a3

IPv6 packet frame type: Ethernet II, hardware address: 80f6-fe00-f4a3

Last clearing of counters: Never

 Last 300 seconds input rate: 0.00 bytes/sec, 0 bits/sec, 0.00 packets/sec

 Last 300 seconds output rate: 0.00 bytes/sec, 0 bits/sec, 0.00 packets/sec

 Input  (total): 0 packets, 0 bytes

        (broadcasts) 0 packets, 0 bytes

        (multicasts) 0 packets, 0 bytes

        (unicasts) 0 packets, 0 bytes

 Output (total): 0 packets, 0 bytes

        (broadcasts) 0 packets, 0 bytes

        (multicasts) 0 packets, 0 bytes

        (unicasts) 0 packets, 0 bytes