Arista Networks (NYSE: ANET) founder and CEO Jayshree Ullal has been selling Arista shares at a ferocious pace over the last six months, dumping about $60 million worth of stock, or 7% of her entire position in the company, since the beginning of the year.

The sales have come during a powerful rally in the stock over the last two months. Arista was trading above $80 recently, after bottoming out around $60 in February. Shares slumped last fall and winter after Arista's chief rival, Cisco Systems, announced it was suing Arista for intellectual property theft. Ullal is a fomer Cisco executive who left the networking giant to start Arista.

The lawsuit, a rare one for Cisco, weighed on Arista shares for several months before investors started to shrug it off. Many Wall Street analysts have built in several millions of dollars in quarterly legals costs and an eventual settlement on the lawsuit, which might be in the triple-digit millions, in light of similar technology lawsuits. A settlement in the hundreds of millions would have a significant earnings impact on Arista but would not put it out of business. The company holds $500 million in cash and is profitable.

It's not unusual for a founder and CEO to sell shares in her company, especially after an IPO (Arista went public in June 2014). It's common financial sense to "diversify" away from the thing that made you rich and either use the money for something else or put it into other assets. The pace of Ullal's selling in recent months stands out from activity last year, where sales were limited by the lock-up on IPO shares. So this is the first two quarters that Ullal was eligible to sell shares.

The table below shows Ullal's sales, according to filings with the SEC.

Source: SEC filings.

One can only speculate as to why Ullal is selling so much stock. This is the first opportunity Arista executives have had a chance to sell shares since the IPO, so it could just be the normal process of diversifying wealth after a liquidity event. But is she also taking a precaution in case the Cisco lawsuit is more serious than believed? Is she taking advantage of the share rally? New vacation home in Hawaii in the works? It's not clear.

When asked for a comment, Arista did not respond.

One thing is true: The timing looks savvy. When Cisco announced its lawsuit, the news hit Arista shares pretty hard -- the stock fell from a high of near $90 per share to a low of $60. So Ullal has been selling large chunks of stock near the company's highest share price in the last year.

Ullal could keep selling for a while and still have plenty of stock. As of June 2014, according to a statement of ownership filed with the SEC, Ullal held 7,462,000 shares. Since then, she has sold 489,760 shares, or 7% of her entire position. That means her remaining shares, about 6,972,000, are worth $578 million at a recent market price of $83.

(Disclosure: No position in ANET stock.)