Monitoring Status and Performance : Viewing Current Flows

Viewing Current Flows
Monitoring > [Appliances] Flows
Flows are useful for troubleshooting and for detailed visibility into the network.
The 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 Flows Are Counted
When it comes to flow and application statistics reports, user-defined applications are always checked before built-in applications.
Ports are unique. If a port or a range includes a built-in port, then the custom application is the one that lays claim to it.
If two distinctly named user-defined applications have a port number in common, then report results will be skewed, depending on the priority assigned to the custom applications. A port is only counted once.
How 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
Pass-through – includes shaped and unshaped traffic
Alert – notifies the user of any issue that might be inhibiting optimization, and offers a possible solution
Choose from Total or Last 5 minutes.
For debugging. A slow device is one that cannot tolerate having its connections accelerated. Generally, this occurs when the WAN side is congested, resulting in too much data on the LAN side. To protect the health of the appliance, you’ll need to disable TCP acceleration in the Optimization Policy.
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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When you Export the data, all default and possible custom columns are included in the .csv file.
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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 exceeds 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
Following is a list of possible errors, along with a brief description and possible resolutions.
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.
2.
WCCP or PBR is not set up correctly to redirect outbound traffic to the appliance. Check the WCCP or PBR configuration on the router.
3.
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.
4.
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 on the Flows page. The Alert details the reason and the possible resolution.
Following is a list CIFS reason codes:
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 on the Flows page. The Alert details the reason and the possible resolution.
Silver Peak supports:
Silver Peak appliances support the following:
Protocol versions: SSLv3, TLS1.0, TLS1.1, TLS1.2
Cipher algorithms: AES128, AES256, RC4, 3DES
Key exchanges: RSA, DHE, ECDHE
Digests: MD5, SHA1, SHA2
Following is a list of the reasons you may receive a failure message for SSL acceleration.
If the resolution calls for removing or reinstalling the certificate, refer to “SSL Certificates Template”.
RESOLUTION: Check the certificate. Possible problems include:
RESOLUTION: Check the SSL protocols on the client and the server. They must be compatible with what Silver Peak supports. If you find that they’re incompatible, you must remove it and install the correct certificate.
RESOLUTION: Check the SSL protocol on the client and the server. They must be compatible with what Silver Peak supports.
RESOLUTION: Check the SSL protocol on the client and the server. They must be compatible with what Silver Peak supports.
RESOLUTION: Check the Subject Alternate Name fields in the SAN certificate. It may be an issue with SAN certificate format or with the certificate not matching the one that’s installed on the server. If it’s incorrect, you must remove it, and install the correct certificate.
RESOLUTION: Contact Silver Peak Support for assistance.
1. Check the appliance syslog messages (that correspond to the client IP address) for SSL errors to determine which TLS extension is not supported.
2. Disable this (these) extensions in the client-side application’s SSL settings. Typically, this application would be your browser.
RESOLUTION: Remove the certificate, and reinstall the correct certificate.
RESOLUTION: Check the client-side application’s SSL cipher algorithm settings to verify that they’re compatible with what Silver Peak supports.
RESOLUTION: Check the client-side application’s SSL protocol settings to verify that they’re compatible with what Silver Peak supports.
RESOLUTION: Contact Silver Peak Support for assistance.
RESOLUTION: Check that the private key file that was installed is correct and matches the server’s private key.
RESOLUTION: Check the SSL server’s cipher algorithm settings.
RESOLUTION: Check the server-side application’s SSL protocol settings to verify that they’re compatible with what Silver Peak supports.
RESOLUTION: Contact Silver Peak support for assistance.
RESOLUTION: Contact Silver Peak Support for assistance.
Active session not found, cannot accelerate the SSL session. The appliance did not participate in the full handshake phase where the certificate information was exchanged between the client and the server.
RESOLUTION: If the certificate is missing, install the correct one. Otherwise, restart the client SSL application.
RESOLUTION: Install the certificate on both appliances.
RESOLUTION: Install the correct certificate and key.
RESOLUTION: Contact Silver Peak Support for assistance.
RESOLUTION: To get full SSL acceleration, restart the application.
RESOLUTION: Install the missing SAN certificate.
RESOLUTION: Configure IPsec on the tunnel.
RESOLUTION: If the Orchestrator shows no SSL certificate, install an appropriate one.
RESOLUTION: On the other appliance, access the Current Flows report, and look at the reason code.(In some cases, the code is displayed only on one side).
RESOLUTION: Check the client-side application’s SSL cipher algorithm settings to verify that they’re compatible with what Silver Peak supports.
Unsupported SSL compression method negotiated.The SSL compression method should be disabled on both the client and the server.
RESOLUTION: On both the client and the server, disable the SSL compression method.
1. Check the appliance syslog messages (that correspond to the client IP address) for SSL errors to determine which TLS extension is not supported.
2. Disable this (these) extensions in the client-side application’s SSL settings. Typically, this application would be your browser.
RESOLUTION: Check the server-side application’s SSL cipher algorithm settings to verify that they’re compatible with what Silver Peak supports.
RESOLUTION: Check the server-side application’s SSL protocol settings to verify that they’re compatible with what Silver Peak supports.
Error Reasons for Citrix Acceleration Failure
When there is an acceleration failure, the appliance generates an Alert link that you can access on the Flows page. The Alert details the reason and the possible resolution.
RESOLUTION: Contact Silver Peak.
RESOLUTION: Relaunch the Citrix session.
RESOLUTION: Check the encryption level setting on the Citrix server.
RESOLUTION: Contact Silver Peak.
RESOLUTION: Contact Silver Peak.
RESOLUTION: Contact Silver Peak.
RESOLUTION: Contact Silver Peak.
RESOLUTION: See system logs. Contact Silver Peak.
RESOLUTION: Contact Silver Peak.
RESOLUTION: Contact Silver Peak.
RESOLUTION: Contact Silver Peak.
RESOLUTION: Contact Silver Peak.
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 Options”.

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