1- on the SRX
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( SRX is the DHCP Client ):
root@srx300-3> show system services dhcp client
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root@srx300-3> request system services dhcp release ge-0/0/0.0
root@srx300-3> request system services dhcp renew ge-0/0/0.0
root@srx300-3> show security flow statistics
Current sessions: 0 Packets forwarded: 7 Packets dropped: 1 Fragment packets: 0 Pre fragments generated: 0 Post fragments generated: 0
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