Monitoring Traffic : Viewing Current Flows

Viewing Current Flows
The Current Flows page retrieves a list of existing connections. The maximum visible number depends on which browser you user.
This section discusses the following topics:
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How Current Flows Are Organized
The following filters are available:
All – all flows
Optimized – optimized flows
Optimized* – these flows originally had a Status of Alert, and the user chose to no longer receive Alerts of the same type
Alert – notifies the user of any issue that might be inhibiting optimization, and offers a possible solution
Choose from Total or Last 5 minutes.
Choose from Anytime or Last 5 minutes.
IP1 (2) / Port1 (2)
Entering 0 in any IP address’s octet position acts as a wild card for that position. 0 in the Port field is also a wild card.
The two IP address (and port) fields are independent of each other. In other words, you can filter on two separate endpoints.
Select which standard or user-defined application (or application group) to use as a filter criteria. The default value is All.
All – all optimized and pass-through traffic.
Policy Drop – traffic with a Set Action of Drop in the Route Policy
Optimized Traffic – the sum of all optimized traffic. That is, all tunnelized traffic.
Pass-through Shaped – all unoptimized, shaped traffic.
Pass-through Unshaped – all unoptimized, unshaped traffic.
[a named Tunnel] – that specific tunnel’s optimized traffic.
Reclassifying the flow is not service-affecting. If a policy change makes a flow stale or inconsistent, then reclassifying makes a best-effort attempt to conform the flow to the change. If the flow can’t be successfully “diverted” to this new policy, then an Alert asks if you want to Reset.
Customizing Which Columns Display
Following are some customization guidelines:
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You can customize by adding the following additional columns:
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Customizations persist across sessions and across users. For a given appliance, all users see the same columns.
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When you Export the data, all default and possible custom columns are included in the .csv file.
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Customize and Export functions are accessible to all users.
 
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To customize the screen display
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To access the Customize Current Flows Table, click Customize.
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Select additional columns, and click OK. The columns append to the right side of the table.
 
Current Flow Details
Silver Peak Support uses the Flow Detail page for troubleshooting.
Most of the information on the Flow Detail page is beyond what is included in the Current Flows table.
Whether the flow is Inbound or Outbound.
When the answer is YES, the Silver Peak appliance is able to intercept connection establishment in only one direction. As a result, this flow is not accelerated. When this happens, it indicates that there is asymmetric routing in the network.
Proxy Remote Acceleration
[Yes/No] If Yes, then this is the server side and the appliance is not accelerating (only the client side accelerates).
Yes means it was signed. If that’s the case, then the appliance was unable to accelerate any CIFS traffic.
No means it wasn’t signed. If that’s the case, then server requirements did not preclude CIFS acceleration.
Overridden means that SMB signing is ON and the appliance overrode it.
Maximize Reduction — optimizes for maximum data reduction at the potential cost of slightly lower throughput and/or some increase in latency. It is appropriate for bulk data transfers such as file transfers and FTP where bandwidth savings are the primary concern.
Minimize Latency — ensures that no latency is added by Network Memory processing. This may come at the cost of lower data reduction. It is appropriate for extremely latency-sensitive interactive or transactional traffic. It is also appropriate if WAN bandwidth saving is not a primary objective, and instead it is desirable to fully utilize the WAN pipe to increase LAN–side throughput.
Balanced — This is the default setting. It dynamically balances latency and data reduction objectives and is the best choice for most traffic types.
Disabled — No Network Memory is performed.
For the outbound traffic, a ratio of the Outbound LAN bytes divided by the Outbound WAN bytes.
When this ratio is less than 1.0, it’s attributable to a fixed overhead (for WAN transmission) being applied to traffic that either is not compressible or consists of few packets.
For the inbound traffic, a ratio of the Inbound WAN bytes divided by the Inbound LAN bytes.
Error Reasons for TCP Acceleration Failure
When there is an acceleration failure, the appliance generates an Alert link that you can access from the Current Flows page. The Alert details the reason and the possible resolution.
Following is a list of possible errors, along with a brief description.
RESOLUTION: Most likely reason is asymmetric routing.
RESOLUTION: Sometimes older operating systems (like Windows 95) do not send the TCP MSS option. You will have to upgrade the operating system software on the endpoints.
RESOLUTION: This is a transient condition. If it persists, take a tcpdump for this flow from both the client and server machines and contact Silver Peak Support.
RESOLUTION: Contact Silver Peak Support for further help.
RESOLUTION: If you want this flow to be TCP accelerated, enable it in the optimization map.
RESOLUTION: Contact Silver Peak Support for further help.
RESOLUTION: This could be due to various reasons:
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The flow is already established before the appliance sees the first packet for the flow. If so, then resetting the flow will fix the problem.
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WCCP or PBR is not set up correctly to redirect outbound traffic to the appliance. Check the WCCP or PBR configuration on the router.
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You have routing issues, so the appliance is not seeing some of the traffic (for example, some packets come to the appliance while others go through another router). If so, you must review and fix your routing.
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If you are in a cluster of Silver Peak appliances, you may have received a flow redirection timeout. If so, you must investigate why it takes so long for the Silver Peak appliance clusters to communicate with each other.
Appliance did not receive a TCP SYN-ACK from remote end within 5 seconds and allowed the flow to proceed unaccelerated. Consequently, the destination IP address has been blacklisted for one minute.
RESOLUTION: Wait for a minute and then reset the flow.
If the problem reappears, the two most likely reasons are: 1) The remote server is slow in responding to TCP connection requests, or 2) a firewall is dropping packets containing Silver Peak TCP options.
Appliance did not receive a TCP SYN-ACK from the remote end within 5 seconds and allowed the flow to proceed unaccelerated.
RESOLUTION: Wait for a minute and then reset the flow. If the problem reappears, the two most likely reasons are: 1) The remote server is slow in responding to TCP connection requests, or 2) a firewall is dropping packets containing Silver Peak TCP options.
RESOLUTION: This could be due to various reasons:
RESOLUTION: Contact Silver Peak about upgrading to an appliance with higher flow capacity.
RESOLUTION: Contact Silver Peak Support for further help.
RESOLUTION: This is a transient condition. You can reset the flow and then verify that it gets accelerated. If it does not, then take a tcpdump for this flow from both the client and server machines and contact Silver Peak Support.
RESOLUTION: Fix the Set Action in the route policy entry.
RESOLUTION: Fix the Set Action in the route policy entry.
RESOLUTION: Upgrade software on one or both appliances to the same version of software.
Flow is not accelerated due to an internal error. Before the previous flow could terminate cleanly, a new flow began with the same parameters.
RESOLUTION: Contact Silver Peak Support for further help.
RESOLUTION: Contact Silver Peak Support for further help. You may want to reset the connection to see if the problem resolves.
RESOLUTION: Contact Silver Peak about upgrading to an appliance with higher flow capacity.
Appliance saw Silver Peak TCP option in the outbound direction. This implies that another Silver Peak appliance precedes this one and is responsible for accelerating this flow.
RESOLUTION: Check the flow acceleration status on an upstream appliance.
Auto-optimization failed because the peer appliance is not participating in automatic TCP acceleration. This can be due to various reasons: 1. Peer appliance is configured to not participate in optimization. 2. WCCP or PBR is not configured properly on the peer side. 3. Routing is not configured properly to send traffic to the peer appliance.
Auto-optimization failed because there is no tunnel between this appliance and its peer, for two possible reasons: 1) Auto-tunnel is disabled. If so, manually create a tunnel. 2) Auto-tunnel is enabled, but needs time to finish creating the tunnel. If so, wait ~30 seconds for tunnel completion, and then reset this flow.
RESOLUTION: This is a transient condition. You can wait for this flow to reset, or you can reset it manually now.
RESOLUTION: This is a transient condition. The flow is in the process of being reset.
RESOLUTION: Investigate why the tunnel is down.
RESOLUTION: Contact Silver Peak Support for further help. You may want to reset the connection to see if the problem resolves.
Error Reasons for CIFS Acceleration Failure
When there is an acceleration failure, the appliance generates an Alert link that you can access from the Current Flows page. The Alert details the reason and the possible resolution.
Following is a list CIFS reason codes. They use the following format:
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No [reason] — The connection is not accelerated, and the “reason string” explains why not.
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Yes [reason] — The connection is partially accelerated, and the “reason string” explains why the connection is not fully accelerated.
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Yes — The connection is fully accelerated.
Sub-optimal read/write optimization due to non-standard server. For example, Windows XP cannot process more than 10 simultaneous outstanding requests.
Error Reasons for SSL Acceleration Failure
When there is an acceleration failure, the appliance generates an Alert link that you can access from the Current Flows page. The Alert details the reason and the possible resolution.
Note  To deduplicate SSL (Secure Socket Layer) traffic, appliances must have a valid SSL certificate and key. For information about installing SSL certificates and keys, see “Adding SSL Certificates and Keys for Deduplication”.
Following is a list of the reasons you may receive a failure message for SSL acceleration.
Resetting Flows to Improve Performance
In the list of Alerts, you can look for the flows that aren’t being accelerated, but could be. Generally, this means flows that use TCP protocol and are not TCP-accelerated:
This includes tunnelized TCP traffic that is not TCP-accelerated. TCP connections are not accelerated if they already exist when the tunnel comes up or when the appliance reboots.
Unaccelerated TCP flows can be reset to allow them to reconnect at a later time. It is assumed that the connection end-points will re-establish the flows. When these flows are reconnected, the appliance recognizes them as new and accelerates them. Note that the time it takes to reset a flow may vary, depending on the traffic activity.
CAUTION Resetting a flow interrupts service for that flow. The appliance cannot restore the connection on its own; it relies on the end points to re-establish the flow. Use it only if service interruption can be tolerated for a given flow.
Tip For information about configuring the appliance to automatically reset TCP flows, see the Advanced TCP Options in “TCP Acceleration”.

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