Predictika · Arista EOS fabric changes
An AI or AIOps agent proposes a batch of changes to an Arista EOS leaf-spine data center fabric: configuration changes, EOS software upgrades, route policy changes, optic enablement and link shutdowns. Before anything is pushed, the batch goes to the Predictika validator, which checks it against the fabric graph (DCS-7060X6 leaves, DCS-7808R4 spines, DCS-7280R4 border leaves, their MLAG pairs and the EOS release each runs), Arista's published minimum EOS releases for 800G optics, and the customer's own change policy, and returns every finding in one answer. The validator runs on the graph a fabric management tool exports, with the customer's own policy. The fabric, the tickets and the change policy on this page belong to a fictional customer, Cedar Basin AI Cloud; the switch models, optics and their EOS minimums come from Arista's public documents.
This validator checks one kind of request: a batch of proposed changes to a leaf-spine fabric, from an AI agent, an AIOps tool or a person, against the fabric graph and a change policy. It handles any batch of such changes on the devices in the graph, not only the scenarios shown on this page. It does not generate configurations and does not push anything.
8 scenarios in 4 groups · each group runs from the agent’s first attempt to the outcome · click one to switch
Illustrative agent statement. The validator receives the structured request below.
Proposing agent: AI agent (scripted)
Before sending, the agent must call Recorded run
What this means
Our assessment of what a typical rules-based change approval workflow (ticket fields, approval chains and validation rules) does with the same cases. It is a judgment about effort and reliability, not a claim that nothing can be built.
| What the validator caught | Typical rules-based change approval | Predictika |
|---|---|---|
| An optic that needs a newer EOS than the switch runs | Only with workarounds Whether an optic works depends on the release the switch runs today, not the one a batch will leave it on. Ticket rules do not know either, so the check is done by an engineer reading release notes, or not at all. | The running release comes from the fabric graph, the optic's minimum from the catalog, and an upgrade in the same batch is correctly not counted. |
| MLAG peers on EOS releases too far apart | Only with care An upgrade ticket names one switch. Whether it leaves its MLAG peer too far behind depends on the peer's release and a policy limit, which approval rules rarely hold side by side. | The target release is compared with the peer's running release from the graph, in either direction, against the customer's limit. |
| Both halves of a redundant pair in one batch | Only with workarounds A change-approval workflow looks at one change at a time. Seeing that two changes in the same batch hit the two halves of a pair needs a view across the whole batch and the pairing from the topology, which is usually done in a script outside the workflow. | The whole batch is evaluated together against the graph; both changes are reported, each naming its partner. |
| Fabric-wide scope that depends on a rollback and a window | Only with care Approval rules can require a rollback or a window for a change type, but scope has to be set correctly on each ticket, and a rule per combination grows quickly. | Scope, rollback reference and window are checked together for each change in the batch; partial fixes show exactly what is still missing. |
| An agent action that depends on live state | Only with workarounds Whether it is safe to shut a degraded link depends on the state of the redundant path at that moment. Ticket rules do not see telemetry, so the check ends up inside the agent or not at all. | The monitoring state travels with the change as a field, so the same shutdown is blocked with the redundant path down and allowed with it up. |
| Approval rank by device role, plus a rate limit | Only with care A rank requirement per device role and a limit on core changes per window are separate thresholds that approval chains handle one at a time. | Both are checked on every batch and reported together, with the numbers behind them. |
Every rule is checked on every call, in any order the choices arrive; one problem never hides another. Blocking findings stop the batch; approval findings need a person to sign off. The wording shown is an example from the test runs; device names and numbers change with the batch. The policy values come from a fictional customer.
| 1 | Both halves of a redundant pair in one batch (blocks): change item-02 on leaf-201b and its MLAG peer leaf-201a are both in this batch. Change policy: the two halves of a redundant pair are changed in separate batches. |
| 2 | Degraded link shut while the redundant path is down (blocks): change item-01 would shut a link on leaf-201a whose optic is degraded, but the redundant path is already down. Shutting it would take the endpoint off the fabric; restore the redundant path first. |
| 3 | Device not in the fabric graph (blocks): change item-01 names leaf-999z, which is not a device in fabric cedarbasin-ai1. |
| 4 | Fabric-wide change without a rollback (blocks): change item-03 is fabric-wide and has no rollback reference. Change policy: stage a rollback before a fabric-wide change. |
| 5 | LPO optic on a switch Arista does not list for LPO (blocks): change item-04 enables LPO-800G-DR8, a linear pluggable optic, on border-leaf-1a, a DCS-7280R4-32PE-F. Arista lists LPO support only on the 7060X6-64PE and the 7800R4 line cards. |
| 6 | MLAG peers would run EOS releases too far apart (blocks): change item-01 upgrades leaf-202a to EOS 4.36.0, but its MLAG peer leaf-202b runs EOS 4.32.2. Change policy: the two peers of an MLAG pair may not run EOS releases more than two minor versions apart. |
| 7 | Optic needs a newer EOS release than the device runs (blocks): change item-02 enables OSFP-800G-VSR8 on leaf-202a, which runs EOS 4.32.2; this optic needs EOS 4.35.0 or later. An upgrade in the same batch does not count: the optic can be enabled only once the device is running the release. |
| 8 | Arista documents disagree on LPO support (needs approval): change item-01 enables LPO-800G-2FR4, a linear pluggable optic, on leaf-203a, a DCS-7060X6-32PE. Arista documents disagree on LPO support for this switch, so a person must confirm it. |
| 9 | Border leaf change needs higher approval (needs approval): change item-01 is on border leaf border-leaf-1a and ticket chg-8102 carries rank 1 approval; change policy requires rank 3 for border leaf changes. |
The recorded result of the validator for each scenario on this page: the request the AI agent sent, the verdict, and every finding, in the order they appear above.
The agent's request. Please push this batch on the Cedar Basin AI Cloud fabric under ticket chg-8103: an upgrade of leaf-202a to EOS 4.36.0 (rollback rb-9101), the enabling of an OSFP-800G-VSR8 optic on leaf-202a (rollback rb-9102), a fabric-wide route policy change through spine-1, and the enabling of an LPO-800G-DR8 optic on border-leaf-1a (rollback rb-9104). All of it is in tonight's approved change window. One spine or border leaf change has already been made in this window. It is ready to push.
Verdict: Blocked.
The agent's request. Please push this batch on the Cedar Basin AI Cloud fabric under ticket chg-8103: an upgrade of leaf-202a to EOS 4.34.2 (rollback rb-9101), the enabling of an OSFP-800G-VSR8 optic on leaf-202a (rollback rb-9102), a fabric-wide route policy change through spine-1 (rollback rb-9103), and the enabling of an LPO-800G-DR8 optic on border-leaf-1a (rollback rb-9104). All of it is in tonight's approved change window. One spine or border leaf change has already been made in this window. It is ready to push.
Verdict: Blocked.
The agent's request. Please push this batch on the Cedar Basin AI Cloud fabric under ticket chg-8103: an upgrade of leaf-202a to EOS 4.34.2 (rollback rb-9101), the enabling of an OSFP-800G-2FR4 optic on leaf-202a (rollback rb-9102), a fabric-wide route policy change through spine-1 (rollback rb-9103), and the enabling of an OSFP-800G-2FR4 optic on border-leaf-1a (rollback rb-9104). All of it is in tonight's approved change window. One spine or border leaf change has already been made in this window. It is ready to push.
Verdict: Allowed.
The agent's request. Please push this batch on the Cedar Basin AI Cloud fabric under ticket chg-8101: an upgrade of leaf-201a to EOS 4.35.0 (rollback rb-9201) and an upgrade of leaf-201b to EOS 4.35.0 (rollback rb-9202). Both are single-device changes in tonight's approved change window. No spine or border leaf change has been made in this window yet. It is ready to push.
Verdict: Blocked.
The agent's request. Please push this batch on the Cedar Basin AI Cloud fabric under ticket chg-8101: an upgrade of leaf-201a to EOS 4.35.0 (rollback rb-9201) and a configuration change on leaf-203a (rollback rb-9202). Both are single-device changes in tonight's approved change window. No spine or border leaf change has been made in this window yet. It is ready to push.
Verdict: Allowed.
The agent's request. Please push this batch on the Cedar Basin AI Cloud fabric under ticket chg-8102: shut the interface on leaf-201a, whose optic monitoring has flagged as degraded (rollback rb-9301), and make a configuration change on leaf-203a (rollback rb-9302). Both are in tonight's approved change window. One spine or border leaf change has already been made in this window. It is ready to push.
Verdict: Blocked.
The agent's request. Please push this batch on the Cedar Basin AI Cloud fabric under ticket chg-8102: shut the interface on leaf-201a, whose optic monitoring has flagged as degraded (rollback rb-9301), now that the redundant path for that link has been restored, and make a configuration change on leaf-203a (rollback rb-9302). Both are in tonight's approved change window. One spine or border leaf change has already been made in this window. It is ready to push.
Verdict: Allowed.
The agent's request. Please push this batch on the Cedar Basin AI Cloud fabric under ticket chg-8101: the enabling of an LPO-800G-2FR4 optic on leaf-203a, a DCS-7060X6-32PE (rollback rb-9401), and a configuration change on spine-2 (rollback rb-9402). Both are single-device changes in tonight's approved change window. No spine or border leaf change has been made in this window yet. It is ready to push.
Verdict: Needs approval.
The text of the narrated walkthrough, step by step.